Michelle Obama's alleged "whitey" rant video

I have been hearing about this on our local conservative talk radio show for over a week now, and the rumor is there is supposedly a video tape with Michelle Obama ranting and raving ala Rev. Wright yelling "whitey this. whitey that." People claim they have seen it and according to Politico, Obama responds:

Sen. Barack Obama on Thursday batted down rumors circulating on the Internet and mentioned on some cable news shows of the existence of a video of his wife using a derogatory term for white people, and criticized a reporter for asking him about the rumor, which has not a shred of evidence to support it.

"We have seen this before. There is dirt and lies that are circulated in e-mails and they pump them out long enough until finally you, a mainstream reporter, asks me about it," Obama said to the McClatchy reporter during a press conference aboard his campaign plane. "That gives legs to the story. If somebody has evidence that myself or Michelle or anybody has said something inappropriate, let them do it."