Even under a conservative projection for the remaining primaries and caucuses, Barack Obama has already built up a big enough lead that his delegate math is unbeatable.

Even if the Democratic Party changes its rules in the middle of the game and seats the Michigan and Florida delegations, Barack Obama's delegate math still gives him a lock on the nomination.

On May 20, Barack Obama will surpass 1,627 pledged delegate, guaranteeing that he will head to Denver with a majority of the democratically selected delegates.