As Democrats elsewhere rub their hands in anticipation of congressional gains in the midterm elections, Democrats in Maryland are gloomily contemplating a scenario in which they may lose a U.S. Senate seat they've held for 30 years. And that scenario has a name: Kweisi Mfume. Smart, personable and politically shrewd, Mfume is not exactly the image of a nightmare candidate. He has the bearing, bona fides and oratorical panache of a senator, and he possesses that priceless commodity for any New Age politician -- a poignant personal narrative. Having run with violent street gangs and fathered five children by four...