http://www.nytimes.com/2007/02/04/weeki ... ref=slogin
A fascinating article on the racial politics of "speaking well."
Biden's recent comments on Obama are a nice example of this. White people often describe accomplished, intelligent African Americans as "articulate," as if it is a surprise or an anomaly. Whereas White people are assumed to have some innate power of speech, it is considered an impressive feat for a Black person to achieve the same level of competency in self-expression.
I wonder if the implied subtext here is that "articulate," when applied descriptively to an African American, really means, "s/he sounds white!"