Looks like Barack Obama's lifelong quest to be recognized as a full-blown black guy is about to take another hit. Oprah is throwing a fundraising mega-bash for her fellow Chicagoan on Saturday. The event is drawing attention not just for its semi-secret guest list (George Clooney, John Travolta) and the pallets of cash it will ship to Obama's campaign account, but also for the speculation it's spawning about the potential impact of Oprah's unprecedented political activism on the electorate.

One constituency that may not be swayed by the big O's endorsement: black voters.

Oprah, known for her Robin Williams-esque ability to flit between her "white" and "black" voice on-air, is detested by some influential African Americans for a perceived bias against central elements of their culture. Well-known rappers have been particularly critical: 50 Cent says Oprah has spent so much time focusing on the interests of white women that "she's become one herself," and that having a public beef with her has reinforced his street cred (apparently the getting shot nine times thing has worn off).

Obama advisers are probably not sweating Oprah's taint on his black guy bona fides too much, but one wonders if it might hit a personal soft spot for a candidate who has noticeably struggled with questions of racial identity both in his personal and political life. If it does, be ready for Obama to ramp up his Ebonics. According to Chicago Tribune reporter and the candidate's biographer, David Mendell, Obama often tries to subdue questions about whether he is "black enough" with "a tendency to overreach in order to fit in with some urban blacks," which some found "a tad off-putting."

Writes Mendell, "Occasionally during his [2004] Senate campaign, he would slap a black man on the back and exclaim something like, 'What's up, brother?' ... I recall one surprised black man responding, 'Huh?' and another not responding at all." Another political reporter told Mendell, "Obama is a great candidate. But that 'hey, brother' thing can be just a little bit too much sometimes.'"