Former Senator John Edwards did not receive an endorsement from David Letterman on CBS’s “The Late Show” Tuesday night, but he did receive eight valuable minutes to woo voters.

The candidate even allowed Mr. Letterman to ruffle through his hair at the end of the segment.

Mr. Edwards’ jokes earned several rounds of applause from an approving audience. After Mr. Letterman recalled the conflict between Senator Hillary Rodham Clinton and Senator Barack Obama at a debate sponsored by CNN on Monday, Mr. Edwards eagerly responded: “What I was trying to do was represent the grown-up wing of the Democratic Party last night.”

Asked how the three candidates get along, Mr. Edwards said “we can’t stand each other,” prompting laughter from the audience and a smirk from the candidate.