[Redbob]

``I am fascinated at the way some African-Americans speak to each other in an English I struggle to understand, then switch to standard English when the situation requires,'' Vilsack wrote..."

Me too, but you're not supposed to SAY that, unless you're Bill Cosby.

[rave123]

I think she is refering to blacks that can speak standard english and jive or ebonics when necessary. Kind of like "when in Rome, do as the Romans". But I think Bill Cosby was talking about blacks that cannot speak anything but ebonics or jive.
This sounds like someone that understands her audience and adjusts accordingly.