Maybe a stretch, but how about Bill Cosby?
I'm not sure which party he's registered with, that's the problem. However, given some of the controversy he's caused among balck people, I could see a few different turns leading him to be favored by the Republicans as a candidate who could bring minorities back to the GOP. (Some of his remarks, made 15 years earlier, could also earn him enough criticism from Democrats that he decides to become a Republica. Or, alternatively, he could be seen as a more moderate Democrat.)
I'm not sure what the POD woudl be precisely, but somehow, instead of trying to return to the big screen in 1987 with a movie he found to be horrible, he starts to get involved with a few other humanitarian things in addition to his hit series "The Cosby Show." Someone in the Republican Party approaches him about campaigning. At first he's too busy with TV, but he begins to become somewhat more interested in the idea of politics.
He begins speaking out on the need for black people to focus on education. He seems like just another celebrity trying to get attention, but someone in the Republican camp decides to push him to become more involved. the party even creates plans to help him run for office if he should choose. (Or, alternatively, the Democrats use him to try to uneat the Republicans there.)
Butterlfies lead to Alren Specter narrowly losing his Senate seat in 1992 (He won narrowly to a political novice in OTL. In fact, if Cosby's a Democrat and pushed hard enough, he could be the one winning.) Cosby, enters state politics after "The Cosby Show" completes its run, and ends up winning a senate seat in 1998. (Either as a Republican or by first winning the Deomcratic primary.)
Cosby gains attention as one of the only black Senators ever, and consistently champions ones ability to "pull oneself up by the bootstraps," noting that he himself had dropped otu of school and then gone back to get his equivalency and gone on to college when he realized how important education was. He makes a name for himself by championing a much more popular version of Bush's "No Child Left Behind" Act, and becomes very well known for pursuing education.
Whichever party he's with, he manages to be the nominee for president. Either in 2004 (ble to beat Bush) or 2008 (he'd be old, but easier to swallow than Obama for some.) Possibly, even in 2000 he could win, I suppose.
Either way, Bill Cosby becomes the first African-American president.