Once upon a time (before the deregulation craze of the 80s) stations had to do this. They were required to give equal time to each political point of view. It was really vague and rarely enforced and most stations just reacted by not showing anything controversial at all.
I still think the best way to turn this trend around is for individual citizens to NOT support the media that is carrying water for the GOP. Do not watch it, do not pay for a subscription to it, and do not do business with the advertisers.
Every progressive in this country should take a hard look at GOP cheerleaders that they are financially supporting in one way or another and stop the flow of funds right away.
http://www.freesqueeze.com