Draftgore.com, which describes itself as a group of grass-roots Democrats, underwrote a full-page open letter to Al Gore in Wednesday's New York Times, imploring the former vice president to enter the presidential campaign. The ad, which says 136,000 people have signed Draftgore's online petition, was published two days before this year's Nobel Peace Prize is expected to be announced. Gore has been nominated for the prize because of his campaign to bring attention to global warming. "America and the Earth need a hero right now - someone who will transcend politics as usual and bring real hope to our country and to the world," Draftgore's letter said.

Monica Friedlander, founder and chair of Draftgore.com, said the timing of the $65,000 ad was a coincidence and not related to the prize.

"All we're trying to do is persuade him that it's a moral imperative for him to be a candidate," said Friedlander, 47, a public relations specialist in Oakland, Calif. She said the group raised the money for the ad with an e-mail solicitation sent out last week, receiving more than 2,000 donations.

Although Gore has said he has no intention of becoming a presidential candidate, several groups around the country are trying to persuade him to enter the race.

"He deeply appreciates the heartfelt sentiment behind this ad and understands where this comes from, but he has no intention of running for president," said Gore spokeswoman Kalee Kreider.

As the Democratic nominee in 2000, Gore won the general election popular vote but lost the electoral vote to George W. Bush after a legal challenge to the Florida result that was decided by the U.S. Supreme Court.

Since then, the former Tennessee senator has worked against global warming and served on corporate boards, including Google and Apple Inc.