I assume that you havent seen too many episodes and dont know too much about the history on south park. But they are known for making fun of everyone, and not selecting by a agenda. For example there is an episode about: Mormons, Scientology, a whole series of episodes on the "superheroes" around jesus, there is even an episode where a future civilization is fighting over the meaning of "AAA", which is a atheistic alliance (to hint on the idea, that there will still be war, even if religions go extinct).

The fact that they make fun of everyone is one of the reasons they stood so long.

Btw in the 2016 season, which they released weekly during the last months of the election, their portraial of Hillary Clinton is the one of an extraordinaly stupid and incompetent woman, while their Donald Trump doesnt even want to be president.