Only two states go to the polls today (and a third caucuses in Hawaii), but if Mitt Romney sweeps them both it could mean an end to the longest Republican primary since 1976.

Polls close at 7 PM Central Standard Time in both Alabama and Mississippi this evening, but winners will not be determined until late tonight. Recent polls in both states show a tight race between all three remaining candidates: Romney, Rick Santorum, and Newt Gingrich, with no candidate more than two points ahead of any other rival.