Larry Johnson of No Quarter Blog is stating that four sources have confirmed a bombshell tape of Michelle Obama exists:

I now have it from two three four sources (three who are close to senior Republicans) that there is video dynamite–Michelle Obama railing against “whitey” at Jeremiah Wright’s church. Republicans may have a lousy record when it comes to the economy and the management of the war in Iraq, but they are hell on wheels when it comes to opposition research. Someone took the chance and started reviewing the recordings from services at Jeremiah Wright’s United Church of Christ. Holy smoke!! I am told there is a clip that is being held for the fall to drop at the appropriate time.

More from Johnson:

But the real reason for Obama’s extraordinary freakout is that he fears the release of the videotape, reported here, of Michelle Obama in the pulpit of Rev. Jeremiah Wright’s church railing against “whitey.” And we don’t mean Whitey Ford. Four Republican sources have told me that the tape exists. I’ve also been informed that Karl Rove and his allies have a copy of it and are using it to raise funds for independent expenditure groups. The tape, I’m told, will be disclosed as the GOP October Surprise. It’s a ticking time bomb.

And I’ve learned that a right-wing Republican billionaire has put a $1 million bounty on the video. He doesn’t want John McCain to win, like a number of conservatives, and thinks Obama is a pathetically weak candidate. The billionaire wants that video released now.

And more:

I know for a fact that Barack and Michelle Obama would like the tape of her blasting “whitey” during a rant at Jeremiah Wright’s church to never see the light of day. They are worried, appropriately so, about the damage this tape will inflict on the Obama campaign. They can be certain of one thing–the tape will hit the blogosphere and TV land come October if Obama is the nominee.

How do I know? I have learned from someone in touch with a senior Republican over this holiday weekend that a major McCain backer has a copy of the tape in addition to the one controlled by the Karl Rove folks. McCain’s supporters are not about to cut Hillary a break. They believe that John McCain stands a better chance of beating Barack rather than Hillary. That’s why they are holding the video. They realize showing it now would likely boost support for Hillary and erode support for Obama among the Super Delegates. Simply put, McCain wants Obama.