“I know what it’s like to be where they are — all of them, from Biden to Clinton,” Mr. Dean said, pushing his fork through a platter of Caesar salad. “Because I’ve been in all of their positions: bottom, middle and top.”

A conversation today with Mr. Dean is a study in discipline compared with his offhand remarks that were prone to generate headlines four years ago. He does not disagree with the assessment, saying he is “unlike the old me.” Why such caution? “You live and you learn, right?” he replies.

So a string of questions are answered with a fresh, yet telling, caution:

Should Al Gore get into the race? “I’ve never discussed that with him, and I don’t plan to. My bailiwick is to stay out of that stuff.” (Mr. Gore, of course, endorsed Mr. Dean four years ago.) After 26 seconds of silence, he changes the subject and asks his lunch guests, “Coffee, strawberry shortcake, anybody?”

If Democrats want the best nominee possible, why not weigh in? “What I tell Democrats is do not vote with your head, vote with your heart.” Did that happen four years ago? “I’m not going to get into that — at all!”

At this point in the race, how do the candidates compare with those 2004? “They’re starting to look presidential, which is how you win.” Pausing for a moment, he laughed. “I’m not sure I ever looked presidential,” he said.

And the campaign? “It’s not as hard-nosed as a race as it was four years ago. The candidates are much more polite to each other.”

While his advisers are in frequent contact with aides to the eight Democratic campaigns, Mr. Dean has spent little one-on-one time with candidates, with the exception of courtesy calls most of them paid to him when the race began. Since then, Mr. Dean has largely watched from afar, overseeing a streamlining of the party’s voter database and other technological upgrades at the committee.