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:
- 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.
- 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
- 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.
