Aggressive, profane, openly scornful of rivals, Ickes rules Clinton's superdelegate operation with an intimidating style and a mythic persona. He is "advisor, consigliere, enforcer and strategist" all rolled into one, says Dick Harpootlian, a former chairman of the South Carolina Democratic Party who backs Obama.

What's more, Harpootlian says: "He's like a shadow. You hear he's here, you hear he's there, but you never actually see him."

In a Clinton campaign that can seem machinelike, Ickes is conspicuous for his idiosyncrasies. A female aide said that when she noticed his dress shirt unbuttoned practically to the navel, it was like glimpsing an unzipped fly.

"I thought someone should have pulled him aside to tell him. I later came to realize that's how he wears his shirts."

And the man in charge of Clinton's feverish effort to lock up superdelegates is Ickes, whose enthusiasm for no-holds-barred politics sometimes rattles friends and foes alike. Ickes once got so carried away that he bit another political operative on the leg. Now, some 35 years later, at age 68, he has mellowed so little that it could happen again.