Joe hates his job as a mall rent-a-cop. He doesn't get to carry a weapon, everyone treats him like a joke, and because he is younger than the other mall rent-a-cops, they make him do all the unpleasant jobs.
On a particularly nasty day at work, Joe is cleaning up vomit in the children's play area and muttering about how much he hates his life.
"We have custodians, but who cleans up the puke? That's right, the guard. Because Bob the custodian took the day off, and nobody can find Sally, and of course Sergeant Frank can't do any work, not while he's trying to flirt with the Victoria's Secret manager. Again."
Earlier that same shift his request for vacation time to attend his parent's funeral was denied, a poodle peed on his shoe, a black kid tried to rob a store and called Joe racist when he intervened, and the crazy lady from that nick-nack shop followed him around for her entire lunch break. So it was understandable that when a six-year-old boy shoved Joe into the vomit he was cleaning up, a little part of Joe called 'self control' broke. The kid actually giggled as Joe stood up, one hand and a knee now covered in curdled vomit-milk. But what really did it was the kid's father, who thought it was so funny, he had to share it with everyone- and started taking pictures with his phone.
Joe vented his rage in a yell and began to storm toward the kid's father. As Joe reached the end of the brightly-lit, padded play area, other on-lookers took notice, and cellphones came out of everywhere to record what was sure to be quite a sight. At that moment, Vick Vickerson happened to back up into Joe's way.
Joe, beyond caring, swears and lays into Vick with all the primal pent-up rage of a 25 year old rent-a-cop with no actual combat training. Wild punches and uncoordinated kicks smashed into Vick, bringing him down and unconscious in moments.
The stunned crowd is motionless. Even the six-year-old boy has stopped flinging puke at other kids as Joe stands panting over the nearly lifeless Vick Vickerson. At this critical moment, a nearby mother asks a very important question.
"Is that Vick Vickerson?" She recognized him from a poster she saw in Walmart just that morning. You know, the ones near the service desk that everyone inspects while waiting for one overworked employee to deal with fifteen angry customers?
The name rings a bell with someone else. With cellphone videos still recording from all directions, Murphy, a retired cop who was sitting on a bench while waiting for his wife to pick out another pair of shoes, exclaims, "That is Vickerson! He's wanted in seventeen states for child molestation and rape!"
Joe becomes an instant media sensation and YouTube celebrity. No less than five different cellphone videos show the pummeling from slightly different angles. His unassuming nature makes him a temporary hit with news crews looking for their one "good story" for the day, and the interview fees and donations from pleased parents across the world enable him to get a 'sick' sports car. After all, Joe is pretty proud of himself now, and certainly not wise enough to keep the money or invest it somewhere.
Only a few weeks later, a sketchy group of business owners decide they need help getting a certain law passed in their state, and the current governor just won't do. Joe's popularity just happens to coincide with the right timing, and these business owners send out Sara, the red-headed seductress, to get Joe on their side. After listening to the "very reasonable" arguments (and a quick marriage to Sara), and with their financial support, Joe runs for state governor. With the behind-the-scenes support of the Business Barons, and with his momentary stardom, Joe wins the election against an unpopular old man accused of corruption.
The Business Barons are no fools, and manage to get Joe a pretty decent group of advisers. Nevermind that Joe unwittingly helps the Barons with their pet projects, the advisers actually do a good job, with Joe reaping the public benefits. When the Barons' coalition falls apart from internal squabbling, Sara sticks it out with Joe, as she has grown used to the perks of being a governor's wife and prefers Joe's honest, if ignorant, personality over the various Barons' manipulative ways.
After a few terms in office, Joe is old enough to run for President. He gets the Republican nomination with his hard stance on crime and successful financial history as governor of his state (despite his advisers doing all the work). Sara's efforts among the rich and powerful to get her husband nominated significantly help his case. Running on a platform of "Just an Average Joe," Joe goes up against a Democrat who, by all rights, should win the election, but in an ironic twist of fate, the Democratic candidate is actually proven to have been born in Cuba, not the USA. Unable to put forward a new candidate in time to drum up sufficient support, Joe wins by a healthy margin.
This book needs to end, so I'll summarize the rest. We now have Joe in his 40s as the American President. Some kind of catastrophe (zombies, alien invasions, nuclear war, polar ice-caps melting...) helps bring the world back together, and Joe is in position to help folks out. Through the clever manipulations of those around him, Joe ends up the nominal leader of just about everything. Something tips Joe off to the questionable activities of his staff, but Sara convinces him to roll with it. A career politician by this point, Joe has learned how to lie well enough when he wants to, and to keep Sara he definitely wants to. Thus Joe controls the world, despite having no real qualifications for the position.