Hill, 25, who plays presidential aide Charlie Young, has a serious case of happy feet. "It was remarkable how poised he was for someone so young," says Martin Sheen, who plays President Bartlet, "but I realized he's been performing since he was a child and he's one of the greatest dancers of all time." The Sayreville, N.J.-raised Hill (father Bert, 51, is an investment banker, and mother Jennifer, 53, is an education consultant) began dancing at 3 because "my mother, brother [Bert Jr., 28] and cousin were dancing, and I just wanted to be around them." Six years later, Hill was appearing in The Tap Dance Kid on Broadway. After hanging up his tap shoes for a few plays and a Disney Channel movie, he returned in 1995 for Bring in 'Da Noise, Bring in 'Da Funk. West Wing calls for him to master another tricky step: an interracial romance with the President's daughter.
Since playing Charlie hasn't required his usual fancy footwork, Hill often retreats from his Studio City, Calif., apartment to meet up with his fellow hoofers back in New York City. "I'm always on my toes," he says. "You can never give up the dance."