[unspun]

I'd say Barack Obama's accent is called Trytosoundlikeanafricanamerican.

[Clemenza]

He doesn't sound very Hawaiian. Methinks he basically lost his accent when trying to sound like an educated Chicagoan and a south side brother at the same time.

From Michelle's manner of speaking, I can tell that she is lower middle class black from the urban midwest. The NYC "black accent" is heavily influenced by the Caribbean as well as from white New Yorkers (listen to Charlie Rangel speak sometime to see the influence of the latter). During the whole ebonics controversy, Bill Cosby pointed out that he was wondering if the educators would use Philly ebonics or Houston ebonics.