Black & Articulate is a Bad Mamma-Jamma

There’s a debate going on in the black community about white politicians calling Barack Obama ‘articulate.’

Why?

Would African-Americans rather have an incoherent, bumbling boob running as a candidate for the Presidency of the United States? Is there something wrong with being educated amd well-spoken if you're black?

If a black person could respond and explain this, I’d truly like to understand. Otherwise I have assume that African-Americans would rather be, perhaps, uneducated?