The updated joke was probably supposed to be something like "Republicans are the new Communists," but it doesn't detonate like a joke. The original movie was an act of comic provocation; this new one turns into a grim and muddled attempt to provoke thought and perhaps outrage. (The only thing I found myself thinking about afterwards was whether this new movie is supposed to take place in a world in which the first movie exists.) To fans of Demme's work from Citizens Band (1977) through Married to the Mob (1988) he's a god among moviemakers, but here he turns out to have a head of clay.
Collateral, directed by Michael Mann from a script by Stuart Beattie, offers about as thoroughly worked-out an allegory as you'll find in movies. Tom Cruise plays Vincent, a hitman, who hires Jamie Foxx's Max, an L.A. cab driver, to chauffeur him around town while he bumps off witnesses set to testify against a druglord. Max is the hero, and Vincent, his antagonist, is a sociopath who feels no qualms about killing for hire. At the same time, however, Vincent represents the kind of assertive masculinity that Max sorely lacks and could use in order to effectuate his business plans, cope with his mother, win the girl.
The script works it out as a progression: first, after Max discovers what Vincent is up to, he fails to beg or buy his way out of staying on as Vincent's driver; then Vincent rescues Max from muggers after Vincent has lashed Max's hands to the wheel of the parked taxi while he takes care of business; then Max gets himself in a position in which he has to convince the druglord that he himself is Vincent; and finally Max uses Vincent's own means to defeat him. Which is to say that Max "has to" take on the parts of Vincent's personality that are, regrettably, useful to a man in this wicked world, and discard the rest. Max, thus, doesn't kill Vincent so much as digest him.
Similarly, Jada Pinkett Smith's Annie is the damsel in distress and, in perfect conformance with the allegory, it's the killer Vincent, confident beyond the bounds of common morality, who necessitates Max's calling her, which Max had previously lacked the nerve to do. It is thus significant (though not interesting) that Annie is the prosecutor out to convict Vincent's druglord-employer by calling to the stand the witnesses Vincent kills. Collateral isn't a work of realism so it doesn't matter as much as it otherwise would that once Vincent has killed the four witnesses it would be unnecessarily risky for him to kill the prosecutor whose case he's already destroyed. What matters is that Annie represents the virtue that Max doesn't discard even after he's taken on Vincent's violent aggression, the visceral sense that right is right that he manfully defends in the climax.