New Yorkers voters in Tuesday's primary are likely to do two things: cool off Bernie Sanders and vault Donald Trump back into front-runner status. The biggest question of the day on both sides is how big the blowouts will be.
On the Democratic side, former Secretary of State Hillary Clinton leads in the polls by an average of nearly 12 points. Sanders oddly claims that the polls are both wrong and that it doesn't really matter if he wins New York.
Sanders may wish this to be true. But it isn't. Clinton currently has 1,758 of the 2,383 delegates she needs to lock down the Democratic nomination with super delegates included. Excluding super delegates, which Sanders claims he can flip to his side, Clinton is still up by 244.
In New York, 291 Democratic delegates are at stake Tuesday. If Clinton wins by around 10 points, she will likely move ahead of Sanders by another 25 or so pledged delegates. That would mean Sanders would need to win around 70 percent of the remaining delegates and Clinton would need just 30 percent. There is pretty much no scenario — barring some major political catastrophe — in which Sanders would dominate the remaining states in such a way.
So if the polls hold and Clinton wins New York by a comfortable margin, the Democratic race will be effectively over, though Sanders is not going to concede and will continue to inflict political damage on the Democratic front-runner. At some point, Sanders will come under heavy pressure from the party to get out of the race. But that won't happen on Tuesday, especially if Sanders shocks the world and makes the race close. If Sanders somehow pulls out a win, the Democratic race will descend into chaos.
On the Republican side, it's all about the district-by-district delegate math. Trump currently leads with 744 delegates to 558 for Texas Sen. Ted Cruz and 144 for Ohio Governor John Kasich. Kasich still trails Florida Sen. Marco Rubio who has 171 delegates even though he dropped out weeks ago.
Trump hopes to take 85 of the 95 GOP delegates at stake in New York on Tuesday. To do that he will have to top 50 percent statewide and in as many of the state's congressional districts as possible. Kasich and Cruz are hoping to snatch at least a few delegates in New York by keeping Trump below 50 percent, especially in Manhattan.
Every delegates matters for Trump because he has little room for error if he hopes to hit 1,237 delegates and avoid a contested convention in Cleveland. Cruz has dominated Trump in securing friendly delegates so multiple ballots at the convention could strongly favor the conservative Texas senator.
If Trump takes 85 of New York's delegates he would need to win around 57 percent of the remaining delegates to hit his magic number before Cleveland. That is by no means a lock but many of the remaining states in the Northeast favor Trump. And the real estate magnate leads by around 10 percent in most California polls ahead of the June 7 primary. The Golden State, which is among the last to vote, awards most of its 172 delegates to the statewide winner.
The Trump campaign claims that if it winds up the nominating process with anywhere close to 1,237 it will somehow find the remaining delegates before the convention. That won't be easy. The only really safe path Trump has to the nomination is to ensure that he doesn't need to court delegates at all and has the number he needs pledged to him on the first convention ballot. That starts by running up the score in his home state.
If Trump underperforms and falls below 50 percent statewide he will be in serious trouble. The same holds true for Clinton. New York primary day is not about who wins, it's about whether the front-runners can crush their rivals' dreams.
—Ben White is Politico's chief economic correspondent and a CNBC contributor. He also authors the daily tip sheet Politico Morning Money [politico.com/morningmoney]. Follow him on Twitter @morningmoneyben.