<These radical figureheads (on both sides)>

That's a bit of a cop out. Just off the top of my head I can come up with the following list of on air right wing hate mongers and I'm sure there are many more:

Glenn Beck
Shawn Hannity
Rush Limbaugh
Laura Ingraham
Michael Savage
Mark Levin
Lou Dobbs
Michelle Malkin

Give me your left wing hate monger list.