Limbaugh is not Coulter, and I think that the "Al Franken and Stewart do it" is more of the demonization of alleged liberals, when a certain mind set dominates the air waves the 'other side is also polarizing' is very weak. If 99% of the polarization comes from one side then it is an interesting argument in rhetoric. When people are liberaly foolish, they usualy don't have the bully pulpit. My favorite of these woo liberal arguments runs like this 'the number of convictions for small time felons is rising based upon obstruction of justice charges, recently a small time felon recieved recieved six years in prison for an obstruction charge. Obstruction charges are the new way to oppresses the (insert here) minority.'. What they don't ever, ever ,ever say is what charges the felon was originaly up on, when they pled to the obstruction charges or what other cahrges were dropped in exchange for just the obstuction charges.
So this great woo arguments is based upon unsound reasoning, that race determines sentencing, when it is socio-economic status that determines sentencing.
However these woos do not have the bully pulpit and they do not influence the media the way that O'Riely, Scarbourogh, Savage and Coulter do, Rush while the original has been supplanted.
Take Noam Chomsky , he cites sources and data, he doesn't usualy use words that are adding to the fire. He does say things that peole don't like but while infuriating his tone is quite moderate.