Democratic presidential hopeful John Edwards (search) was the talk of NBC's "Tonight Show" (search) even before he walked on stage Friday night.

During his opening riff, host Jay Leno (search) joked about Edwards' tradition of taking his wife to Wendy's for a Valentine's Day dinner.

"That should be his platform," Leno said. "Any guy who can convince his wife to go to Wendy's every year on Valentine's Day should be elected. Imagine what he could convince the leaders of other countries to do."

Later, during an interview with guest Diane Keaton (search), the actress professed her admiration for the Democratic senator from North Carolina, saying she watched him everyday on CNN and was thrilled to meet him in person.

"Now that I'm nominated (for an Oscar), I feel like I'm in a race too. I think about him and I don't know how he's doing this," she said. "It's hard to be out there and be substantive and be involved and be excited."

Edwards welcomed the compliment.

"I was very pleased to hear that," he said during a brief exchange with reporters. "I think the world of her and my wife loves her."

Edwards was in California to make several campaign and fund-raising stops.

During the show, he touched on such issues as gay marriage and the loss of U.S. jobs to overseas workers. If elected, Edwards said, he would support the right of individual states to decide whether to allow gay marriage.

"If California chooses to recognize same-sex marriage, that's fine and the federal government ought to honor it," he said.

Edwards also said he believes major policy changes are needed to prevent companies from shipping jobs overseas. He said he would support placing environmental regulations on countries that take American jobs.

"Right now we've leaned so far into free trade that we've forgotten what fair trade is," he said.

Edwards also chided Leno for a slip of tongue during the show, in which the comedian called him a vice presidential candidate.

The candidate, who has said he's not considering running for vice president, responded that he could support an Edwards-Kerry ticket.