Biden was slated to share an uncomfortable lunch with President Barack Obama on Thursday, following his disastrous week on the campaign trail, which culminated with a racially inflammatory warning to African-American supporters that Mitt Romney will “put y’all back in chains.”

But Biden’s chain claim was especially damaging because it diverted attention from the Democrats’ criticism of Gov. Mitt Romney’s running-mate, Rep. Paul Ryan.

It also helped Romney persuade swing-voters that the Obama campaign is divisive and hateful, in contrast to Obama’s 2008 “hope and change” message.

“Mr. President, take your campaign of division and anger and hate back to Chicago,” Romney said during a Wednesday speech in Ohio.