Why are the comics tougher on Bush than the Democrats?

Tonight, on HBO, comic Lewis Black eviscerates George Bush, Dick Cheney and right-wing fundamentalists in a funny, biting way that the leaders of the Democratic party -- or even many progressives -- don't have the nerve or wit to do. (I saw the show live in May, and his take-down on Bush's cluelessnss while visiting amputated Iraq vets is a masterpiece of dark comedy and expert timing, joined by a hilarious defense of evolution and the fossil record against the ignorance of "intelligent design" advocates.)

Earlier in the week, Jon Stewart took on Bill Bennett over gay marriage with a devastating rebuttal of the right's notion that gay marriage threatens heterosexual marriage. He staked a clear moral ground on civil rights and gays as part of the human family, as opposed to the legalisms over state's rights that most Democrats used in opposing the gay rights constitutional amendment.

Perhaps the comics are showing us the way towards the "authenticity" that so many political experts say the public wants to see in their candidates, and that the consultant-driven presidential candidates of the Democratic Party in recent years have lacked.