Hip-hop impresario Benny Boom, who has directed videos for P. Diddy, Lil' Kim and LL Cool J, didn't need to have his arm twisted to join an anti-Bush advertising campaign.

"I felt like Bush stole the last election and the whole country kind of got robbed and bamboozled, and I wanted to make sure I did my part besides voting," he says. When he was approached by the liberal MoveOn PAC, "I was like, yo, I want to do an ad myself."

A celebrity-saturated effort to defeat the president kicks into high gear tonight in New York with a premiere featuring music by Moby, the Roots and Natalie Merchant, and appearances by actor Kevin Bacon, Boom, liberal radio hosts Al Franken and Janeane Garofalo and onetime candidate Howard Dean. The opening-night glitter is designed to publicize the forthcoming MoveOn advertising campaign, which includes all manner of famous people.

Actress Rebecca Romijn-Stamos gets behind the wheel of a car and stars in an ad, co-authored by Norman Mailer's son, called "Stranded Republicans." Woody Harrelson writes, directs and stars in "Cheney Is Not on Our Side." Martin Sheen, the "West Wing" president, voices a spot written by John Sayles.

The list goes on. Margaret Cho stars in an ad she wrote, while Matt Damon voices a spot called "The Disappeared." Actor-turned-activist Rob Reiner directs and voices "The Mistake," while Illeana Douglas and Ione Skye appear in an ad written by Franken. Scarlett Johanssen, Ed Asner and Bacon provide the voices for an animated spot called "Who Profits?"

"Most people don't involve artists and their talent the way we're involving them," says Laura Dawn, the MoveOn official who served as executive producer. "Usually you ask the artist to come, we take a pretty picture and that's how you raise money." Those who are lending a hand, says Dawn, "are just as appalled by Bush administration policies as anyone."

Moby, who has been working with MoveOn for some time -- including holding a bake sale at his Manhattan restaurant -- contributed a track from his album "18" for an environmental ad called "The Air We Breathe."

"What galls me to the core of my being is when George Bush pretends to be a cowboy," says Moby, recalling that he grew up near the Bush family estate in Connecticut. "It galls me that they've created the largest federal deficit in the country's history. It galls me that they basically lied about the reasons for starting a war in Iraq and alienated our allies. The list of things that gall me is too long to get into."

Moby concedes, though, that "on the one hand I'm guilty of indulging in the slanderous, base name-calling that often attends political debate."

Bush campaign spokesman Terry Holt dismisses MoveOn as "quite an extremist organization" and scoffs at the effort, saying: "All the showbiz in the world isn't going to get John Kerry elected president." Referring to Bruce Springsteen's decision to do fundraising concerts for the Democratic ticket, Holt says: "John Kerry may have The Boss, but we have the commander-in-chief." He acknowledges, however, that celebrities can help draw attention to a political message, which is why Wayne Newton, Stephen Baldwin and Bo Derek will be at next week's Republican convention in New York.

The MoveOn spots are edgier, angrier and in some cases funnier -- not to mention riskier -- than anything Bush and Kerry have thrown on the air. The group is not releasing details of the ads until their official unveiling today.

"This is a way of breaking out of the Washington consultant ad frame and doing something more entertaining, creative and original," said Eli Pariser, executive director of MoveOn PAC. "Our hope is that it will better connect with voters because it's not the same old stuff."

Asked about the heavy recruitment of celebs, he says: "If we could get attention for these issues without a Rebecca Romijn, we'd do it."

Boom's ad is a voter-registration pitch aimed at minorities. "A lot of common people in the inner cities just don't see the importance of it because nothing changes," he says. MoveOn describes the ad as an attempt "to counter Republican voter suppression efforts."

There may be less to the ad hype than meets the eye, however. While the 12 spots will be made available online, says Pariser, only one or two may hit the airwaves, depending on how focus groups react in the 18 most tightly contested states and how much money MoveOn members contribute toward the campaign.

"I'm not working under any grand assumptions that my involvement will change the course of the election," Moby says. "My great fear is that we will wake up on November 3, George Bush will have won and we will say, 'What more could we have done?' "

What is striking about the spots is that they contain no mention of the Democratic presidential nominee.

"I'm more passionate about being opposed to Bush," says Boom. "George Bush is probably the first real gangsta we have had in office. John Kerry needs to be a little bit more of a gangsta himself."

Moby is among the musicians set to perform at tonight's premiere.Hip-hop director Benny Boom crafted an ad for MoveOn, urging minorities to register to vote.