What are some plausible factors and societal changes that could result in a modern civil war in the United States?

Question

I am working on a short story that will take place somewhere twenty and fifty years from now and I want there to be a civil war occurring in the United States. I have seen a lot of speculative fiction that depict intriguing dystopias but I feel like a lot of them aren't plausible. Like even when partisan tensions have been high in the US in the last 150 years, it continually does not result in literal civil war. The only civil war we had was primarily caused by one of the most divisive issues in our entire history: slavery. I don't know if we have that kind of modern equivalent.

What possible events and/or societal changes would have to occur for America to plausibly have a second civil war?

Answer 1

Lots of people think we're currently on the verge of Civil War 2.0

Or that we're already in a "cold civil war". Haven't you heard the Claire Wolfe quote?

“America is at that awkward stage; it's too late to work within the system, but too early to shoot the bastards.”

Civil War 2.0 already has a nickname: the "boogaloo". No few observers expected it to turn hot this Monday in Virginia. That state has a new government that has promised to confiscate privately held firearms, and the citizens had a particularly large demonstration to tell their government to stuff it. Not unlike Massachusetts in 1775. So it's definitely the area to watch.

I don't want to start an argument about politics here (it's a habit I'm trying to kick), just wanted to point out that it should be pretty easy to research real-world reasoning why people think the boogaloo is nigh. If you want "plausibility", no speculation here is going to be more plausible than what's really happening.

NB: Hope I haven't frightened anyone. It'll all probably turn out to be nothing. Now excuse me, I've got to make another trip to the big box store for another truckload of canned food for the bunker...

Answer 2

The system under the Constitution in the USA makes that kind of fracturing pretty hard.
What makes it harder now is that a steady increase in power of the federal government has reduced the amount of power that each state has.

If you look at the Civil War in the 1860's, the wedge issue was slavery. The precipitation events, though, wasn't slavery itself, but the desire of the southern states to leave the Union. The war didn't start until the southern states seceded (left) from the union and formed their own government. There was enough resources in the South that it would do a lot of damage to the North if the secession were allowed to stand. This is kind of a top level view, but it gives a sort of basis for a future conflict.

If you want a civil war, you need a situation where there is a wedge issue, it's big enough for very large groups of people feel it right to leave the rest of the US, and that the resources of the areas leaving are substantial enough to be worth invading those that choose to leave (keep in mind, political capital is a resource.)

To throw out an idea:

Say there is a wedge issue over personal firearms ownership (I'm picking this kind of out of the air.) The 2nd amendment of the constitution gets repealed or some such. Now, Texas, Louisiana, New Mexico, and Arizona decide that they want to keep the right to keep and bear arms and they secede from the union They decide to form the Republic of Texas.

Here is the kicker that would lead to war: Texas has Oil. Texas has coastline. Louisiana has the Mississippi river delta. A bunch of oil platforms are in the Gulf of Mexico and many of the most productive oil refineries. Without those, the Republic of Texas could conceivably cripple the US economy if trade stopped. That would be a logical reason for war.

Of course, if it was just New Mexico that tried to leave, there wouldn't be much of a war because NM would be rapidly overwhelmed and it doesn't have all that much in the way of resources.

So that's what you need. A reason and enough resources to be at stake.

Answer 3

To steal from the book Unwind-- abortion is a big one. One side believes that the other is literally murdering babies, so they're primed to fight. The other see sit as a form of slavery for women due to the choices of others, so they're also primed to fight. Boom-- civil war.

I think that income inequality might finally boil over into a civil war at some point. Look at the Russian revolution-- it came about because of vast income inequality as the proletariat seized the means of production-- IE, the working class got sick and tired of getting paid starvation wages while their employers reaped massive economic profits and enjoyed wealth and luxury beyond anything that they could dream of. Kinda sounds like those CEOs with their golden parachutes who have been making billions off of stuff like Uber, dismantling Sears, taking money from the bailout in '08 and then running, etc. You could easily have the people who have been barely scraping by on minimum wage, who are up to their eyeballs in debt pushing back and taking over the local government in their area. I think it's especially feasible in a world where we've seen further automation and greater economic developments in competing economic powers such as China, which could further erode the number of jobs available. Some people will be decently well off ("I'm not rich, but I make enough to get by, and I don't want to lose all of that! If I side with the rich people, I'll probably have a better chance of keeping it!") while others will be desperate enough to kill ("I'm dying of diabetes, but some jerk who runs the pharmaceutical company charges $700 a dose! I can't pay that much!"). Perfect mix.

You could just have the spark be a particularly corrupt politician, who is clearly only in the role to further their own goals. Back in the day, we tarred and feathered politicians when we knew just how corrupt they were, and it wasn't a terribly pretty sight. I think it's pretty feasible that someone would try to do that to their elected official, and that it would spark ongoing violence with police, as copycat groups figured that it was actually a great move. Counter-protestor groups get involved, someone starts shooting, someone else starts shooting back, and before you know it, you've got a three-way war going in a town or two as the police try to prevent members of two very angry political parties from killing one another.

Answer 4

A lot can happen in twenty to fifty years.

Let us say that we finally figure out AI. We can build robots that can actually follow orders and be smart about it. Neat!

Except... these robots put a lot of people out of work.

So, on one side we have a large mob of unemployed angry people.

On the other side are the industry owners. Fewer, but better organized and well equipped. Also using robot soldiers.

To confuse the issue there is also "robot rights activists" who claim that these robots are slaves that should be emancipated. They will side with the mob against the "slave owners", but they are really a separate faction.

Answer 5

An election season in which the left leaning Democratic party took control of both sections of congress AND the Presidency could lead to a civil war.

I will try to keep this as neutral as I can because I personally hate the party system and think it causes basically every heavily polarized political argument in our country.

As the United states has a long history of fighting anything that isn't capitalism, the fact that the democratic party leans heavily towards socialism would make it reasonable that if they took control of 2 of the branches of government, they would be likely to start pushing through major social reforms. Taxes, gun laws, welfare, civil rights, basically every major issue would very quickly be legislated towards the left.

This, understandably would very quickly anger the right leaning, conservative Republicans who look at socialism as an equivalent to communism, and by all accounts, the plan of the devil (not even exaggerating that one). As conservatives lean pro-gun rights, and the staple argument is that they should have guns if they need to defend themselves from a tyrannical government, it therefore makes complete sense that at least a notable portion of the conservative population would be likely to attempt to liberate the country from it's socialist overlords.

At this point you can fill in the intervening riots and and government responses. The interesting point here would be that ON AVERAGE (not as a rule, and varies by region) most Police and Military personnel lean conservatively right. So it would be their job to follow the orders of a left leaning government, despite the fact that many of them lean right in their personal views. This could lead to a rift both between military and police, as well as within each organization.

Personally, I think it would be more likely that the military would majority side with the federal government as per their training to having sworn to obey the orders of the president, while law enforcement (many of whom have military training) is much more likely to follow regional majority. I would think that although the military has the structural and resource advantage, the liberal federal government would likely hesitate to use force. Meanwhile, radical conservatives paired with like-minded local law enforcement would be quick to form a reasonably large militia force.

By the time full fledged rebellion has been declared it is likely territory would be divided very much like the first Civil War, with the conservative South east leading the charge against the more progressive North east (I lived in Tennessee and have heard way too many people say "the South will rise again"). The west coast states will likely to be dominated by left leaning progressives, but will be solidly cut off from the northeast by the very conservative Utah and Idaho, (Arizona, Nevada, and New Mexico will be a toss-ups).

This is just some personal thoughts on possible events. I could honestly keep going with this for ages.

Answer 6

I want there to be a civil war occurring in the United States

I don't, but I understand this is an hypothetical and academic view of the subject :)

even when partisan tensions have been high in the US in the last 150 years, it continually does not result in literal civil war.

(Emphasis added): Good observation. The reasons and value backdrop for this are outlined in the Federalist Papers. Even with the divisive issue of slavery, dissolution of the union has always been considered less acceptable by Americans than allowing tensions and even sharp disagreement continue for as long as necessary to win the issue peacefully and maintain union. From Federalist No. 6:

Commercial republics, like ours, will never be disposed to waste themselves in ruinous contentions with each other. They will be governed by mutual interest, and will cultivate a spirit of mutual amity and concord.

To your question:

What possible events and/or societal changes would have to occur for America to plausibly have a second civil war?

The Declaration of Independence gives us some ideas, as does the 1861-1865 American Civil War, specifically South Carolina's "Ordinance of Secession." These are the primary documents behind which the initiators of the two great secessions of America in modern times rallied the people behind their cause. While one could critique particularly the latter of containing propaganda, these are nonetheless significant documents because their purpose was to galvanize behind them an armed fight for independence. These documents, unlike textbooks, could not afford to misrepresent the perceived injustices which would justify secession in the minds of most of their constituents, for fear of losing that fight.

The South Carolina Ordinance of Secession models itself heavily after the 1776 Declaration of Independence, and attempts to derive its legitimacy therefrom. Consider the nature of some of the alleged offenses common to both:

• Invasions against property rights
• Failure to uphold the rule of law, in particular due process
• Loss of sovereignty and representation
• Inciting the populace to insurrection
• Replacement of local social institutions

Specifically, unique to the 1861 Civil War: "The denunciation of slavery as a sinful institution", and the election of a president whose opinions they didn't like.

So, if you wanted to look for modern, current events and societal changes that could provoke a similar event, it would be most reasonable to look for these themes.

1. Where are property rights being increasingly violated?
2. Where is the rule of law not being upheld, particularly due process?
3. Where are citizens being denied sovereignty and representation?
4. Where are local people being intentionally divided, angered, and incited to rebellion?
5. Where are local social institutions being displaced and replaced systematically?
6. What very popular, entrenched and usually lucrative practices are being denounced as sinful?
7. Has it ever happened in recent history that a president was elected whose opinions were very unliked by nearly half the population?

My guess:

1. Socialism, welfare programs 2. Identity politics, political targeting 3. Illegal immigration and ballot rigging 4. Mass media 5. Public education, erosion of religious freedom, attacks on family and states' rights. 6. Drug abuse, human trafficking, abortion, money laundering 7. Reflect on your own prejudices for a second. Thanks. At least you've now identified them as such.

Constitutionally-adherent citizens are not going to be responsible for initiating aggression, and will in many cases have to suffer tremendous injury before acting in self-defense. They would rather that the Federalist condition of union prevail, despite differences and even abuse. This is the American track record, which you highlighted.

Answer 7

I don't think things like gun rights or abortion access are good hooks for a story about another civil war. Fundamentally, we've had those issues around for years, and we haven't had a civil war yet, so it seems less likely. Plus, if you choose one of those, you'll have to put the protagonists on one side or another. So, you'll be making a work that is very tied to political allignment. If that is your goal, that's fine, but if not, I'd pick something that isn't already so heavily partisan..

Looking forward, I think a good candidate would be AI-based automation obsoleting most of the workforce. While providing worker protections is more in the Democratic party wheelhouse currently, it is less of a party defining issue than it has been historically, so you can probably realign groups as necessary to make your story work.

This also has the benefit of being somewhat similar to the cause of the previous civil war. That is, of course it was about slavery, but one of the things about slavery at the time was that industrialization had started and slavery was becoming obsolete as a result. The political reality needed to shift to recognize the economic one -- that the North, with a head start industrializing, was going to be calling the shots for the time being, and the South was going to lose prominence. And one thing the North didn't like was spreading slavery across the country -- it doesn't fit as well in an advanced economy and it was generally considered evil and cruel by most of the developed world.

Heavily AI based automation could produce a similar economic shakeup. Presumably somebody could suggest a redistributive solution, which would essentially take us away from capitalism. There are all sorts of details that would need to be worked out, so you have plenty of leeway to come up with something evil and cruel to be the proximate cause of a war.

Just as an example that runs counter to what I suppose is the assumption that Democrats would push for the redistributive solution:

Perhaps there's a massive realignment and you have two completely made up parties: "The American Workers Party of America" (a nativist socialist party) and "US, inc" (a capitalist internationalist party, sorry you'll need a better name). Surely you can find shades of whichever party you like and whichever you dislike in either, and you can probably find plausible cleavage points in the modern parties to split each roughly in half and form these parties. You can retcon some events of the last 20 years or so to build up to this realignment. 70 years is a while, so it seems plausible, right?

The AWPOA proposes massive taxation on big business and international trade, which will be redistributed to Americans whose jobs are made obsolete. The degree to which the payouts are targeted specifically at their constituents, and the degree to which their party excludes various minority groups, is a knob you can turn to determine who will be the protagonists. These taxes lead to massive economic devastation in the Tex-Cali corridor (which has become a huge population center similar to the Bos-Wash corridor but much larger, and a huge tech hub). They decide not to enforce these taxes, one thing leads to another, and war happens.

Texas, California, Nevada, and New Mexico together is about 25% of the US GDP now, so the supposed corridor plus various surrounding states could be a plausible alliance to make it an interesting civil war, particularly assuming the economy follows a trajectory that is plausible, but favorable to your story.

Answer 8

One huge item that would prevent this is that the US Military is no longer made up of state militias, and military groups are no longer composed of people from single states. Bases in California or Texas, for example, are not manned soley or primarily by Californian or Texan loyalists.

So for your story, you may need to have the military be deliberately split into state or region based forces. I'm not sure what justification you would need to come up with for that to happen, but without a divided military, another US Civil War would be very short.

Answer 9

Perhaps not a civil war, but rather a coup d' etat

Back when I was in staff college, we were all required to read LTC Dunlap's paper on "The origins of the coup of 2012" - because in the mid 1990's, that was far enough into the future, but close enough to contemporary times, to resonate with us. The bottom line from my seminar leader was: "We are here to support and defend the Constitution, not to rule" - and variations on that theme.

Here is the paper. Take yourself back to the year 1993 and read it with the political context of that time in mind.

Here are some core points that LTC Dunlap considered in "the unlikely happening" - a coup d'etat ,bloodless, and a Junta in charge in DC.

From the intro:

The letter that follows takes us on a darkly imagined excursion into the future. A military coup has taken place in the United States—the year is 2012—and General Thomas E. T. Brutus, Commander-in-Chief of the Unified Armed Forces of the United States, now occupies the White House as permanent Military Plenipotentiary.
His position has been ratified by a national referendum, though scattered disorders still prevail and arrests for acts of sedition are underway. A senior retired officer of the Unified Armed Forces, known here simply as Prisoner 222305759, is one of those arrested, having been convicted by court-martial for opposing the coup. Prior to his execution, he is able to smuggle out of prison a letter to an old War College classmate discussing the “Origins of the American Military Coup of 2012.” In it, he argues that the coup was the outgrowth of trends visible as far back as 1992. These trends were the massive diversion of military forces to civilian uses, the monolithic unification of the armed forces, and the insularity of the military community. His letter survives and is here presented verbatim.

Factors included in the speculative paper:

1. Americans became exasperated with democracy. We were disillusioned with the apparent inability of elected government to solve the nation’s dilemmas. We were looking for someone or something that could produce workable answers.
2. Since then voter participation has steadily declined. By 1988 only 50.1 percent of the eligible voters cast a ballot. Simple extrapolation of those numbers to last spring’s Referendum would have predicted almost exactly the turnout. It was precisely reversed from that of 1964: 61.9 percent of the electorate did not vote
3. Congress initiated the use of “national defense” as a rationale to boost military participation in an activity historically the exclusive domain of civilian government: law enforcement. Congress concluded that the “rising tide of drugs being smuggled into the United States . . . present[ed] a grave threat to all Americans.” Finding the performance of civilian law enforcement agencies in counteracting that threat unsatisfactory, Congress passed the Military Cooperation with Civilian Law Enforcement Agencies Act of 1981.20 In doing so Congress specifically intended to force reluctant military commanders to actively collaborate in police work. This was a historic change of policy. Since the passage of the Posse Comitatus Act in 1878, the military had distanced itself from law enforcement activities.22 While the 1987 law did retain certain limits on the legal authority of military personnel, its net effect was to dramatically expand military participation in anti-drug efforts. By 1991 the Department of Defense was spending $1.2 billion on counternarcotics crusades.

I'll let the paper speak for itself if you are interested in seeing how a change from within might take place.

Caveat: since 1993 some things have changed.

First and foremost, the political reaction to the War in Iraq has eroded public trust in the Military as problem solver that is a highlight of that paper. But I offer this answer because I'd like you to see how someone took a very similar idea that you have, and projected 'what was' into 'what could be'. If that paper serves its purpose of getting you to do a little "what is into what might be" that is enough.

What makes this answer relevant to your question is: a civil war, or a complete change in the character of the nation, may not take the form that you expect. It is as likely to come from within and be a shock to the system when it arrives.

A note on the Source:
The Origins of the American Military Coup of 2012, by Charles J. Dunlap, Jr., was first published in the Winter 1992-93 issue of Parameters.

Answer 10

"Free the slaves" and "State rights" were probably not something 95% of the population was willing to kill or die for ON ITS OWN. It is a slogan that subsumes the indirect links of regional (eg states rights, returning escaped slaves) and most importantly personal (eg jobs, taxes and tariffs) concern. Similar occurs in insurgency wars ... land rights, fuel price rise makes my taxi uneconomical, foreign occupation, that policeman didnt get punished for mistreated my sister.

The answer to your question is a matter of building the indirect links to the overall slogan of choice.

Using climate change as the example slogan, the USA might grow increasingly divided between green (renewable) and brown (fossil) states and it overlaps with partially related divides eg new tech vs old tech (surveillance, wealth, factories, environment) and liberal vs conservative (guns, abortion etc).

some headline "green" issues

• A project like the Dakota pipeline requires the modification to a highway ... why should the green state (that doesn't have the oil wells or refinery) pay ?

• Is inspection of tanker trucks passing through a renewable fuel only state legitimate state law enforcement or harassment ? Do the delays resulting from these inspections count as (unpaid, non driving time) rest for the truck driver under wage and OSHA regulations for all three states she crosses through ?

• States vs federal laws (eg marijuana). A hacker in a brown state remotely disables the engine of a hybrid federal vehicle in a green state, causing a fatal accident just outside the federal "reservation". This potential hero to the green staters was protesting the new anti-hunting regulations being enforced by his local National Park.

Answer 11

If you're going for alternate history, I'd suggest changing Lincoln's election so that he appeared on all ballot forms, and there wasn't a huge amount of discontent at his election.

Ergo, no US civil war in the 1800's. I imagine slavery getting illegalized sometime much later, with slave-power being voted out of Washington and civil rights reforms happening at much the same time.

I think the core of making a modern civil war plausible requires there to be no past civil war. The way the US one went sort of set a precedent. (Don't try.)

Answer 12

To understand a cause of any civil war, we should not consider official books as they to proclaim very poetic reasoning (moneybags vs poverty, slavery vs freedom etc). Actual reason is the same, all the time: there is an issue that's not resolved for decades. So at least one generation of people is grown at the environment that splits the society into beneficiaries and infringed ones. Combined with weaken government power, that triggers the war around.

Back to your case: let's hunt for the issues! The worst they are, the better for the story.

• Immigration laws and black labor market
• Healthcare and work safety
• Crime gangs and police violence
• Strange international politics and enormous budget expenses
• etc

That way, we can create a story-line:

• Sarcastic (like vegans vs green-eco as vegans do annihilate plants that give us an oxygen and green-eco are to cut-off the humanity by 50% or more to save the Mother Earth)
• Noir genre (a son of illegal immigrants trying to escape from the war and being non-welcomed on both sides)
• Thriller (a hero starts to fight on one side and then discovers an unpleasant truth causing him to twist the side)
• Melodrama (family man left his wife and kids at a shelter to fight for their future, then stumbled across a complex situation with a nasty beauty involved, and she's on another side)
• etc

Answer 13

Money. Microsoft's headquarters in Redmond, WA develop a new currency. The West Coast is tired of Washington D.C. and the East coast favoring the East Coast at a federal level. The East Coast favors the old system where America, controlled by the East Coast, in in charge of the nation's currency. The East Coast has NYC which is central to lots of economics, but West Coast's Los Angeles is also a power house.

So the West coast seeks to secede in the future, just as the American South sought to before. The East Coast doesn't want to lose the "sea to shining sea" aspect, and fights to preserve, strongly mirroring much of the reasoning of the first civil war.

Answer 14

Long ago, the Supreme Court ruled that kicking Cherokees off their land would be illegal. We did it anyway, with the full support of the elected president.

The vote counts for impeachment of Trump, and the current inflammatory rhetoric from both sides in the senate tells me that neither side is interested in truth and justice. And long before this circus, I was saying the difference between them is which parts of the Constitution they want to ignore.

Given the the suggestions of violence I keep seeing (from extremists on both sides), and calls to “resist” from those not so extreme, it would not surprise me for a legislation to be countered by a court decision, and the extremists for and against to commit violence. But the next civil war (if it happens) won’t be region against region. It will be neighbor against neighbor.

Some might think violence against neighbors is unlikely. But more than once when I lived near a university, I witnessed football fans celebrate a win by destroying their neighbors’ property.

Answer 15

Perhaps global warming might cause sufficient internal friction to eventually trigger a civil war in the US. There appear to be many who do not want to believe in global warming in part because of the implication for capitalism. And there are many who accept that changes must be made, that growth cannot continue for ever and that the Governments of the world need to take drastic action. I can’t see either side backing down, but I can see more and more people being convinced that something drastic must be done prompted by increasingly horrific incidents like fires and flooding of large cities (New York or Boston perhaps caused by a hurricane that far north?).

At some point the majority of the people would forcefully conflict with the conservative political elite and vested interests in the oil industry and other big businesses. If no action were taken there might be a revolution, but if a party willing to take the necessary drastic action were voted in it might be equally destructive politically. It might appear as fantasy now (and hopefully will remain as such) but the situation will get a lot worse before it gets better and such horrors cannot be ruled out.

Answer 16

Civil war could be initiated by a major natural disaster, a surge in organized crime, or a prolonged economic crisis that the government is unable to substantially mitigate. If the government is perceived as impotent, it becomes much more likely that states, cities, or even neighborhoods would be driven to form their own governments, and be successful in doing so. After some time, the central government might attempt to reassert control. A state that has seceded might find itself fighting both the central government and smaller groups that want to secede from the state, but which also oppose the central government.

Answer 17

Inequality and lack of social mobility in the US today are higher than they have been for most of the 20th century. Wealthy people who commit crimes escape with light penalties. The first time he was caught, Jeffrey Epstein was given a deal so favorable that he was able to return to preying on children soon after. The Sackler family built a multi-billion dollar fortune based on the strategy of deliberately addicting millions of people on opioids, which has resulted in over half a million deaths in America. Today the Sacklers are negotiating to give up some 3 billion for reparations while keeping another 13 billion stashed offshore for themselves, with no serious effort by anyone to put them into prison. Not bad for being drug lords.

We keep seeing the phenomenon of candidates losing the popular election yet winning the presidency. Similar things happen with other elections such as gerrymandering, voter suppression, etc. Election campaigns are dominated corporate money and political action committees with hidden sources of funding. Few people believe that "one person, one vote" reflects the reality of elections. Courts and judges are viewed as partisans by both sides. Americans today have much less faith in the system than previous generations did. The election of Donald Trump can be seen as the culmination of this kind of lack of faith in the system; people would rather throw a hand grenade into the works than listen to traditional politicians spin lines about fixing it.

Every social issue in the news tends to polarize around the two main parties. People identify with their own social group and demonize the other. Urban vs rural. Abortion. Gun control. You name it. Everything filters through the lens of Republican vs Democrat. Good vs evil. Us vs them. No compromises.

What I'm describing is essentially something like the social conditions in France prior to 1789. In short, nothing radical is necessary to move the United States to civil war. It just needs to stay on its current course and we'll get there. The trigger issue that sparks that fire could be anything, but the tinder is already being put into place.

Answer 18

The answers so far posit a regional separation.

Look at other examples:

• England with the war of the roses. (Rival claimants for the crown)

• England during the Cromwell Period. (Protestant vs Catholic)

• Irish troubles was/is nominally a conflict about Protestants vs Catholics, but under the hood is more a case of class warfare: By in large the Catholics were not property owners.

• French Revolution was really class based civil war.

• France 16th century: Problem between Huguenots (French Calvinists) and the established Catholics. The Huguenots were, I think about 10% of the population at it's peak.

States are tied together firmly with trade right now. To get a civil war, you need to go irrational: People have to be willing to take a serious economic hit out of rage our outrage.

Possible plausible scenarios:

Scenario 1. Regional based economic secession.

Trumpist style federal government cuts programs that benefit 'blue' states. California passes a law requiring that all taxes be paid to the State of California who then forwards payment to the federal government. Federal returns are no longer required. Enough Californians are pissed off with the federal government that the vast bulk of individuals and corporations co-operate.

Federal returns become an unenforceable law. As programs to California are cut, California reduces transfers to Washington.

Washington, Oregon, many other blue states follow suit. Neighbouring states amalgamate many services. Non-neighbouring states form a federation.

This can develop in various ways:

A: Becomes the new norm. While nominally part of the U.S. California and like states have in effect severed their political ties. The degree of trade with the remains of the U.S. can vary depending on your scenario.

B: Same thing happens internally in some states. California, Oregon and Washington rural areas east of the Cascades/Sierras attempt to separate from the state. Most will try to negotiate becoming part of the adjacent state (Nevada, Idaho) This results in a patchwork at the country level. Depending on how the adjacent states get along, this may become an uneasy truce, or a bunch of essentially self sufficient fiefdoms.

C: Is resisted by the remaining states. This is complicated by the number of defence establishments that are in blue states. The western seaboard is essentially cut off at the passes over the coastal mountain ranges. Many red state units called up are very short staffed, as lots of individual soldiers aren't happy with shooting at other Americans.

Overall military units using high tech gear quickly run out of material. Too many things are produced in multiple locations, and assembled on a Just In Time basis. Many red state units are essentially decapitated, with largely liberal officers refusing orders, or establishing 'white mutiny' or other forms of non-compliance, passive resistance.

D: The Trumpist Government uses nuclear weapons against recalcitrant cities. Given the distribuition of nuclear weapons, this doesn't end well.

Scenario 2: Religious/Racist based civil war.

In this scenario the irrational fundamentalists / disaffected trump style supporters decide they are going get rid of the polluting dark skins/catholics/jews/. The scary bit about this, they have a large fraction of the firearms. It starts with a single mid sized city in the rust belt passing a law that certain groups have to leave. They are given a short period to do so. A local militia shoots/hangs/burns alive outspoken members who protest. The state governor who hails from that city decides to see how this will play out, and does NOT call out the National Guard to restore order. Media coverage by social media and drones is very thorough. This instantly polarizes the people especially in the red states. Other cities follow suit. Small towns put up signs: "No Niggers, spics, chinks, papists or kikes allowed in city limits after sundown." Catholic churches, and baptist churches with largely black congregations are burned.

Like the Rwanda massacres, people are given the choice: Kill that (other) or die.

Telling the players apart is difficult, at least telling a white racist from a white tolerant person is difficult. There is no obvious class, language, or accent difference.

This will NOT be on a state level, but will be at a much finer granulation. Take a look and red vs blue counties in the last election. For examples look at Myanmar, Rwanda, and Cambodia.