There's now a new "magic number" of delegates that a candidate needs to win the Democratic presidential nomination. Before Saturday's meeting of the Democratic National Committee's Rules and Bylaws Committee, that number was 2,026. Now, with the addition of delegations from Florida and Michigan, it's 2,118. Still, Barack Obama's campaign says its candidate hasn't lost any ground and is fewer than 50 delegates away from going over the top.

The Obama camp made up the difference with superdelegates from Florida and Michigan, who were previously told they would not be seated at this summer's Democratic convention but now have half a vote each, and by capturing an estimated 17 of Puerto Rico's 55 pledged delegates. As of this post on Monday, the Obama campaign had announced endorsements from two additional superdelegates, Democratic National Committee member Jerome Wiley Segovia and Nancy DiNardo, who chairs Connecticut's Democratic Party. These endorsements, the Obama campaign says, brings the Illinois senator just 44 delegates away from the nomination.

According to Domenico Montanaro of NBC's First Read blog, Obama now needs to win about 19 percent of the delegates still up for grabs (that is, both pledged delegates and superdelegates who remain uncommitted) in order to become the nominee. Clinton, on the other hand, needs to win about 85 percent of them. This math can vary, because estimates of the delegate count vary depending on who's doing the counting.

It's worth remembering, though, that these numbers are anything but hard and fast. No delegate is absolutely bound to vote for a particular candidate; even pledged delegates may vote however they like at the Democratic convention. And the Clinton campaign is indicating that it will be trying to peel away superdelegates who've endorsed Obama. While flying out of Puerto Rico Sunday night, Clinton herself told reporters, "One thing about superdelegates is that they can change their minds."

Thirty-one pledged delegates are at stake in the last remaining Democratic primaries, which will be held in Montana and South Dakota on Tuesday. The Obama campaign reportedly wants to be able to declare victory on Tuesday, with the (pretty solid) reasoning that Tuesday night is the best time to get real national attention for a victory speech, what First Read calls a "movie-ending moment." Obviously, this means there are not enough pledged delegates remaining to give Obama the win by that time, so his campaign will have to add enough superdelegates to make up the difference. According to First Read, and its unidentified sources, the chances that will happen are "better than 50-50."