(To sum it up, the president's daughter has been kidnapped and Snake is the only man for the job to save her. I swear to God, '90s action movies have hands down the most convoluted and inefficient plots ever.)
What They Got Right
Los Angeles is indeed very dirty and shitty. And the aggressively Christian president in the movie was elected in 2000, the year George W. Bush, who was also known for his strong religious views, took office. Carpenter was prophetic enough to know that America in 2000 would be craving a down-home, "country boy" president to take America back to a simpler time where folks knew their manners; he just assumed we'd want one as a response to a massive earthquake instead of a few harmless White House blow jobs.
What They Got Wrong
There are some sci-fi and speculative fiction books and movies that really try to anticipate what the future will look like. The original Star Trek got quite a bit right, as far as day-to-day technology goes. Even if writers miss the mark more often than they hit it, they at least try.
Escape from L.A. didn't come close. To anything. I mean, Carpenter has insanely advanced technology, like holograms and power-dampening remote controls, but everyone still shoots regular pistols and dresses like they live in the '80s, and they surf out their problems, apparently.
The biggest issue is that Carpenter refused to commit to where he thought America was going morally. The whole country was being consumed by sin and excess, but we still inexplicably elected a strict, hyper-moral dictator-president for life. Leather-clad gangs roamed the streets, but we still wanted our man in office to think eating red meat was a crime punishable by exile. Maybe Carpenter was predicting how divided our nation was going to be in the 2000s, but it seems more likely to me that he's just a child who likes leather jackets.