Why is the Right Wing Talk all we hear on the radio

I have a theory as to why we only hear from the Right Wing talk shows (this does not include the RGV where without satellite radio you have no choice). Most Democrats are more diverse that the right, not as likely to be so single minded or non-diverse in their thoughts. Take the abortion question, where the right wing media including Planet Fox would have America believe that it is a vast left wing conspiracy of card carrying Democrats that, in league with Satan and the ACLU (you won't convince them that it is not one and the same), is the hardcore belief of every democrat. When actually, here in the Valley you see a diverse stand among Democrats as in most of the country regarding that issue. The issue, is not as hard an fast among traditional Democrats. Some of my favorite liberals (and I use the word with affection, not contempt) would rather listen to music or a book, than to have a commentator with questionable credentials, tell them what to think. I, of course, do not include the common sense commentators like George Lopez or Carlos Mecia and others. What about you?