No real politicians in this game is the right call and it is genuinely new for them
Rockstar have confirmed the satire targets consumer culture, media and American life generally, and that they are not putting real political figures in it.
Previous games have been much closer to the line. The talk radio in the old ones went directly at named public figures and at very specific real arguments. This one is aiming at the shape of things rather than the people in them.
I think that is the right decision and not for the reason people assume. Naming real figures dates a game instantly. A joke about a person is dead in five years. A joke about the machine that produces those people is still funny in twenty.