Why would that matter? Sister Soulja and Jesse Jackson are both black, and that's where it came from......
The Sista Soulja phrase came from the 92 Clinton campaign where he was forced to repudiate the violent (or sexual?) lyrics of a black rap musician by that name.
Since then, the media has always talked about candidates having to distance themselves from people associated with their core voters.
They used the term with in the 2000 campaign wth Bush and (the conservative mostly white Carolina based college... name escapes me right now).
I even saw it used recently relating to Hagee and McCain.
My point is that I don’t think the media has enough guts to use it now againt their hero Obama.