You know that awkward moment when you forget someone's name at a party? Or when you don't remember a close friend's birthday? Or when you just can’t recall that time you endorsed your political nemesis as a real “conservative”?

Okay, so you probably haven't had to deal with that last one, but Republican candidate Rick Santorum is dealing with unwelcome memories this week. Frontrunner Mitt Romney launched two ads featuring Santorum endorsing the former Massachusetts governor in 2008, during Romney’s first White House bid. The videos, produced just days before a critical primary vote in Illinois, feature Santorum saying “if you want a conservative as the nominee of this party, you must vote for Mitt Romney.”