Rick Santorum may be pinning his last ditch hopes on the Pennsylvania primary to boost his waning campaign, but in reality it's impossible for the former Senator to catch up to Mitt Romney, given his runaway lead in the delegate count. But, that doesn't mean Santorum can't inflict another kind of damage on the former Massachusetts governor. There's still a chance that he, Ron Paul and Newt Gingrich can collectively prevent Romney from locking down a majority of delegates before the convention in Tampa, Fla. at the end of August. This is the only realistic hope by which a candidate other than Romney secures the nomination.
The Yahoo News Delegate Calculator, below, is designed to let you gauge the odds that Romney can reach his mark. Use the sliders and buttons to input your predictions for the forthcoming contests, and we'll automatically tally the numbers and tell you whether any candidate has reached the magic number of 1,144 delegates needed to secure the nomination.
While we've tried to make this feature as straightforward as possible, the delegate process is rather complex. Below you'll see a primer on how to use this interactive take on delegate math, since these sought-after votes will ultimately determine who will face President Barack Obama in the fall.