Why are there no syndicated Democratic talk radio shows?

Typically I listen to talk radio for a few minutes on the way to work and the entire way home. What I've noticed is that all the major and even minor talk-radio stations that deal in political commentary or analysis are very staunchly Republican. I wonder why daily.Why are there no syndicated Democratic talk radio shows?
Radio is part of the free enterprise system and exists on ratings numbers and advertising sales.



For various reasons, conservatives are more likely to become listeners, than liberals. Conservatives tend to like to discuss political matters, current events, economics and ideas and liberals often prefer to talk about specific candidates and campaigns. The former generates topics more easily adapted to talk show formats and the latter seems to work better as guest appearances on news programs rather than sustained conversation and on-going discussions on talk radio.Why are there no syndicated Democratic talk radio shows?
Al gore and others started one but it failed miserably in no time at all. I think it was called Air AmericaWhy are there no syndicated Democratic talk radio shows?
NPR has a lot of liberal-slanted stuff.