The antiwar group MoveOn.org joined forces with famous actors, musicians and directors to organize a new ad contest: “Obama in 30 Seconds.”

Obama supporters are asked to send 30-second spots revealing their view of Obama’s campaign, in order to win a $20,000 gift certificate for a camera and editing package. The winning ad will be aired on national television.

Participants can send their entries until April 1 and MoveOn members, estimated to be around 3.2 million, will vote them after watching them on the MoveOn website. The top 15 ads will then be judged by a group of liberal activists and stars in the industries of music and film.

Among the judges will be Ben Affleck, Matt Damon, film director Oliver Stone, musicians Moby, Eddie Vedder and John Legend, civil rights leader Jesse Jackson.

“MoveOn’s ‘Obama in 30 seconds’ ad contest is a chance for everyone, from aspiring filmmakers to armchair pundits, to raise their voices to put Obama over the top and help make history,” Academy Award-winning actor Ben Affleck said.

The contest encourages participants to be as creative as they want, but it does not allow personal attacks on anyone. Official rules say that the ads are supposed to be about Barack Obama and should not refer at Hillary Clinton or other Democratic candidates for presidency. The Bush administration is to be mentioned only in contrast with Obama.

MoveOn launched a similar contest, named “Bush in 30 Seconds,” in 2004, in which around 1500 entries competed for the grand prize. The winning ad pictured several children doing adult jobs, concluding with the question “Guess who's going to pay off President Bush's $1 trillion deficit?” The ad became one of the most watched political commercials.