Delegate math: How Tuesday could close door on Sanders bid

WASHINGTON -- Hillary Clinton can't win enough delegates Tuesday to knock Bernie Sanders officially out of the presidential race, but she can erase lingering honest doubts about whether she'll be the Democratic nominee soon.

After her victory in New York last week, Clinton has a lead over Sanders of more than 200 pledged delegates won in primaries and caucuses.

As she narrowed Sanders' opportunities to catch up, Clinton continued to build on her support among superdelegates -- the party officials who are free to back any candidate they choose at the Democratic national convention in July.

In the past two days, Clinton has picked up 11 more endorsements from superdelegates, according to an Associated Press survey.

Factoring in superdelegates, Clinton's lead stands at 1,941 to 1,191 for Sanders, according to the AP count. That puts her at 81 percent of the 2,383 delegates needed to win the nomination.

Democratic presidential candidate Bernie Sanders speaks during a rally Saturday in Baltimore.Patrick Semansky ~ Associated Press

At stake Tuesday are 384 delegates in primaries in Connecticut, Delaware, Maryland, Pennsylvania and Rhode Island. This group of contests offers Sanders one of the last chances left on the election calendar to gain ground in pledged delegates and make a broader case to superdelegates to support him.

Yet it appears Clinton could do well enough Tuesday to end the night with 90 percent of the delegates needed to win the nomination, leaving her just 200 or so shy.

The Sanders campaign knows a tough battle awaits in those five states and says it will reassess its campaign after Tuesday. If Sanders fails to win in the latest primaries, he won't have another chance to draw closer in a big way until California votes June 7.

Clinton is on track to have hit the magic number of 2,383 by that point.

A look at the paths forward for the two candidates:

Sanders' hope

After losing New York, Sanders needs to win 73 percent of the remaining delegates and uncommitted superdelegates to capture the nomination.

That's not too realistic.

So his campaign is arguing the Vermont senator can flip superdelegates at the July convention in Philadelphia, especially if he were to overtake Clinton among pledged delegates. To do so, Sanders would need to win 59 percent of those remaining.

The Sanders camp acknowledges that will require a win in Pennsylvania, the biggest prize Tuesday with 189 delegates. Sanders is trailing Clinton by double digits in preference polling in the state. His campaign also believes he can pick up delegates in Connecticut, where 55 are at stake.

Sanders would recapture some momentum with such an unexpected big-state win, but he can't escape the fact Democrats award delegates in proportion to the vote. Even the loser gets some.

That means a close victory for Sanders in Pennsylvania probably would be offset by the results in Maryland. That state, the second biggest prize of the night with 95 delegates, is a Clinton stronghold.

The upshot: To catch Clinton, Sanders needs big wins in the delegate-rich, racially diverse states still left to hold primary elections.

The problem: His next win by such a wide margin over Clinton in such a state would be his first.

Clinton's path

If Clinton were to win four or five states Tuesday, as preference polling suggests, she will extend her pledged delegate lead to about 300.

The most likely scenario: big hauls in Pennsylvania and Maryland and modest gains in Delaware, Connecticut and Rhode Island.

At that point, she would need to win just 35 percent or so of the remaining delegates from primaries and caucuses to maintain her lead in pledged delegates. In actuality, she's been winning 55 percent so far.

More significantly, doing well Tuesday likely would cement her support among superdelegates. Clinton holds a 513-38 advantage among those party officials. An additional 163 superdelegates have yet to commit, but many have told the AP they ultimately will support the candidate who wins the most delegates in the primaries and caucuses.

Never before have superdelegates lifted a candidate to the Democratic nomination when he or she trailed in pledged delegates.

With superdelegates included, Clinton's lead after an average performance Tuesday would require Sanders to start winning far more than the three of four delegates he needs just to catch up.

Do a little better than that, and Clinton reasonably can expect to clinch the nomination by June 7 -- before the first votes are even counted in California.