Obviously, one concern people have with Barack Obama's candidacy is that they worry that a black man faces intrinsic electoral problems. I would say that the flipside of this is that an African-American Democrat probably has more latitude to say
sensible things about affirmative action (via Jon Chait who sees this as part of a
growing populist trend in Obama's rhetoric) that would get a white candidate in hot water with supporters he's counting on.
This article available online at:
http://www.theatlantic.com/politics/archive/2007/05/obama-on-affirmative-action/42597/