But in New York, the real estate mogul is in his element.
Polls show him poised to dust Cruz and Kasich in the state's primary, giving him the opportunity, in an election-night event set to take place at Trump Tower, to reassert his standing as the Republican front-runner.
Trump is leading by double digits in most polls of the state
, but for all his claims in every campaign speech that America will get sick and tired of all the "winning" it'll do with him as president, Trump is now a candidate in need of a big win.
The Texas senator has proven an ability to out-organize Trump
at recent state conventions, where he's picked up key victories that could come in handy if the Republican convention goes to multiple ballots in July. Kasich, meanwhile, poses a pesky threat among moderates.
As Trump reshapes his staff for complicated state-by-state delegate selection battles, he'd get a shot of momentum -- and a big pile of delegates -- by easily clearing the 50% hurdle.
The delegate battle
"No New Yorker can vote for Ted Cruz," Trump declared at his rally in Buffalo on Monday night -- or Kasich, for that matter, given the Ohio governor's vote in Congress for the North American Free Trade Agreement.
But some New Yorkers might -- and it could cost Trump delegates.
The Empire State has 95 delegates, but only 14 of them are awarded at the statewide level. If he breaks the 50% mark, Trump would sweep those
The other 81 are divvied up three apiece among each of the state's congressional districts. In some areas, Trump is sure to crack 50% and win all three -- but elsewhere, Cruz and Kasich could hold Trump under that mark and limit his delegate edge, or even best him and claim more delegates.
Each district will be closely watched. With Trump's path to 1,237 increasingly narrow and Cruz and Kasich angling to pick off scores of those delegates on the second ballot at the Republican National Convention
in Cleveland if Trump doesn't reach that number, every delegate is crucial.
Pennsylvania, Maryland, Connecticut, Rhode Island and Delaware are on deck for next week -- and the campaigns will be studying the results in New York's moderate suburbs and elsewhere to see if there are similar areas where more delegates could be picked off in the contests to come.
Can Clinton score a big margin?
Clinton won election twice from New York to the Senate. She defeated Barack Obama in New York in 2008. And on Tuesday, she'll try to put the Democratic nomination out of Sanders' reach by running up a big margin of victory.
"I am hoping to do really well tomorrow. I am hoping to wrap up the Democratic nomination
," Clinton said during a visit to an LGBT phone bank on her behalf on Monday, to raucous applause and chants of "Hillary, Hillary."
She was quick to hedge, saying: "But, but, but -- I am not taking anything for granted. I have to quickly add that before anyone has the wrong impression."
Still, a big win would give Clinton's campaign more ammunition to argue that Sanders has no plausible path to the lead in pledged delegates, or even the popular vote.
For Sanders, the hope is that New York will follow the national Democratic polls
, which have shown the Vermont senator increasingly close to Clinton -- tying or surpassing her in some cases.
But the national polls, at this stage, might not mean much. The majority of the Democratic electorate has already voted, and many of the states left on the calendar have heavy minority populations that tend to benefit Clinton.
A win in New York, though, would give Sanders a way to shake up the psychology of the race -- significantly strengthening his claim that he can still win and potentially tipping Democrats who are still on the fence into his camp, much like challenger winning undecided voters at the late stages of a general election against an incumbent.
Fixing the problem spots
There are two fundamental questions in the Democratic race: Can Clinton eliminate Sanders' massive advantage among young voters
? And can Sanders minimize Clinton's huge lead among minorities?
If the answer to either of those questions is "yes," it would mark a significant shift in the race.
The exit polls will reveal whether anything has changed. If it hasn't, there's no real reason to expect the Democratic race overall to be shaken up.
Sanders spent much of his time campaigning in Brooklyn
, making it a good spot to watch for signs of a surge that he'd hope to carry into places like Maryland and, later, California.
One factor that could significantly hamper Sanders: New York is a closed primary, which means only registered Democrats can participate -- blocking him from bringing in the infusion of independents that are often critical to his victories.
Sanders said on CNN's "New Day" on Monday that he'll win if voter turnout is "very high" -- but he acknowledged that, with a closed primary and Clinton's edge among loyal Democrats, "we're kind of spotting Secretary Clinton a whole lot in that regard."
One unique feature of New York's primary: Three of the remaining five presidential candidates have lived in the state -- and they're fond of reminding voters of it.
It'll make for interesting election-night viewing to see whether each wins those areas.
Will Sanders run up a big margin in Brooklyn, where he grew up?
Does Clinton get some distance in her adopted residence of Chappaqua, and other suburbs like it?
And how will Trump perform in Queens, where the brash Manhattan/Floridian was raised?