But aides to Mr. Sharpton said Mr. Stone's role is far more central. The aides said that he consults with Mr. Stone about once a week and that Mr. Stone helped give shape and purpose to a campaign that was floundering.

Mr. Stone has advised Mr. Sharpton before national debates, encouraged him to implement a ''rapid response'' system, and introduced him to the man who became his national campaign manager, Charles Halloran, the aides said. Mr. Stone provides ideas and direction, while Mr. Halloran, who was an aide to Bill Clinton in his first campaign for president, does the front-line work.

In the attacks on Dr. Dean, for instance, Mr. Stone helped set the tone and direction while Mr. Halloran did the research. Mr. Halloran came up with Dr. Dean's hiring record as governor, for example, aides to Mr. Sharpton said.

It is Mr. Sharpton, of course, who ultimately decides what he will say and how he will say it. As for Dr. Dean, he has stumbled for many reasons, but he was deemed hurt by the attack, as well as Mr. Sharpton's criticism in an earlier debate over Dr. Dean's remark that he wants ''to be the candidate for guys with Confederate flags in their pickup trucks.''

By all accounts, Mr. Stone is not being paid. So why he is doing it?

Tucker Carlson, the conservative co-host of CNN's ''Crossfire'' and another unlikely friend of Mr. Sharpton's, says he thinks it is because he, Mr. Stone and Mr. Sharpton all have ''disdain for white liberals.'' In his first autobiography, Mr. Sharpton expressed delight at holding street protests in New York because: ''Their facade is exposed. The great Northeastern liberals aren't so liberal anymore.''

Others say the explanation is that Mr. Stone just enjoys the rough-and-tumble of politics. He has been accused more than once of dirty tricks and, some political strategists believe, is enjoying egging on Mr. Sharpton, not necessarily to advance Mr. Stone's political agenda, but to satisfy his appetite for throwing a monkey-wrench.

''Roger doesn't have to get paid and he doesn't have to do politics,'' a political operative who has worked with Mr. Stone said. ''He has enough money. He is doing this because it's easy and it's sexy.''