Here are two articles in the L.A. Times about today's launch of the left-wing Air America Radio. This one by Al Franken tells what he hopes to do. This one by two other guys says it won't work.
I suspect, merely as a matter of prediction, the odds favor the latter view. A friend of mine in the restaurant business once said, "If every time someone opens a new restaurant you predict it will fail within a year, you'll be correct a pretty impressive percentage of the time." New radio ventures probably work about the same way.