In the 1970s something like FoxNews--undisputedly non liberal, and some would say even conservative--would never have existed. Also, there are conservative radio stations including but not limited to Rush Limbaugh to counteract the liberal biased broadcast TV networks. Voting along party lines is stupid, but it was and still is largely influenced by biased media outlets.
And for the record, I intend to register as an idependent when I'm old enough to vote.