As voters from 10 states across the country head to the polls on Tuesday, Republican candidates will be hoping to secure as many of the 437 delegates as possible. To win the party nomination, a candidate must obtain more than half of the total 2,286 delegates at the Republican National Convention. That means that what happens today could change the entire course of the primary season. Mitt Romney may be leading the pack, but he’s still far from acquiring enough delegates to become the nominee. The last race that was this close was in 2008 between Hillary Clinton and Barack Obama.