Courageous? That's a stretch. He's objecting to broadcasting changes which threaten his particular niche in the market. If he wants to fight censorship, he'd be well-advised to organize and seek a Congressional hearing on the matter. Stern could become sort of the anti-Tipper, which would probably win him more friends than his current approach.
Ranting on the air and blaming the President for matters which are not decided in the Oval Office is plain old smear politics and is easily seen as such. He won't win many new fans with his agitprop - and his current fans are more interested in mindless, crude entertainment than they are political activism.
"Fartman the Formidable"
They will not be pleased to see him removed on obscenity charges and if, as seems likely, obscenity is used as an excuse to remove political opponents and critics, you can kiss the Bush administration good-bye.