Rob, I guess it's a number of factors. Since FCC chair Michael Powell is the son of Colin Powell, and Mike Powell is the one going after indecency now, Stern probably ties the fact that Powell has this job to the fact that the Bush administration is in power.
Also, it's not just the indecency thing Howard's objecting to. He's objecting to Bush's religious beliefs being used in his decision making (stem cell research, Iraq, etc.), and Bush's seeming arrogance.
So I think Howard has several reasons to want Bush out. Not just the censorship.