These people have money. They have fame. Those two things together can influence idiotic youths more than any scientific study produced by any reputable Academic source, and you know this.
I'm all about parody, I wouldn't mind at all if "actors" were evenly split between conservative and liberal...that's just not the case. Hollywood is overwhelmingly liberal (probably because none of them ever had to actually work for anything...I cite Tom Cruise and others comparing a movie shoot to active duty in a warzone), and the PSA's and other media that comes out of Hollywood is unfairly biased...
Wait...it's unfair! Even the playing field! We're all supposed to be equal, right? Why do Libs in Hollywood get more air time than Conservs?
edit: Freudian slip...parody=parity.