I started paying attention to politics about six years ago, and I've been listening to talk radio since then. Over this six-year span, I've live in two radio markets -- Nashville and Knoxville -- and neither has had (or even tried, not that I blame them) a liberal host. Chattanooga had a liberal guy named Hightower, but I think they dumped him. It's funny how the liberal talkers just don't seem to pan out for the radio stations.
I would probably listen to a thoughtful, rational, entertaining liberal, just to have my ideas challenged if nothing else.