IN MY FIRST LIVE VISIT with the announced candidates for mayor of Philadelphia Wednesday night at the University of the Sciences, my immediate impression of the would-be Democratic nominees was "Three Bald Black Men and a Rich White Guy." From left to right that's moderator, Marc Howard, of Channel 3, and candidates Michael Nutter, Dwight Evans, Dr, Foster (Green Party) and Tom Knox. Before the start of the candidate's forum, seasoned pols, Nutter and Evans, comfortably worked the West Philly crowd with grins and handshakes like, well, like they were running for mayor. Knox, the rich white guy, seemed uncomfortable pressing the flesh with strangers. Chaka Fattah (hereafter known as the Black Candidate With Hair) was a no show at the event in his own congressional district. Nutter and Evans were the most effective speakers, both armed with experience and savvy, but if I had to declare a winner of this early skirmish, I'd have to give the nod to Dwight Evans, who was the only one of the crew who reached a delivery that I'd call passionate about why he wants to be mayor.