By Trip Gabriel

New York Times

Donald Trump’s grasp of the Republican presidential nomination drew closer with his victories in three states Tuesday night, and the chances of party leaders wresting it from his hands at a contested convention were a bit remoter Wednesday.

By winning Michigan, Mississippi and Hawaii, Trump captured most of the 150 delegates at stake Tuesday, and his mathematical path to a majority of 1,237 delegates needed to secure the nomination is increasingly brighter than his rivals. He needs about 54 percent of outstanding delegates; his closest rival, Sen. Ted Cruz of Texas, needs 62 percent.

But Trump gained something even more valuable than delegates Tuesday: momentum as the race heads into a watershed moment, March 15, when the first states that award delegates winner-take-all hold their primaries. They include Sen. Marco Rubio’s home state, Florida, and Gov. John R. Kasich’s, Ohio. Both men now have their backs to the wall, fighting for their political lives.

“The only person that has a shot of getting 1,237 is us given how well we did last night,” said Barry Bennett, a senior adviser to Trump, who is closely tracking the delegate race for him. He said “the clock is ticking” on other candidates but “not necessarily on us.”

“After Florida and Ohio,” Bennett said, “if we win both those states, Cruz will be 300 delegates behind. The winner-take-all states are the rocket fuel.”

Cruz did better than polls predicted in Michigan and Mississippi, and he won a commanding victory in Idaho. In all, he netted an estimated 57 delegates to Trump’s 71.

But Cruz, who trails Trump in delegates awarded so far by an estimated 462 to 358, is facing a primary map of big states in the North and West that are demographically more favorable to Trump. He seemed to acknowledge the difficulty of overtaking Trump before the convention even if the race becomes the two-man contest he has long sought.

“Look, Reagan and Ford battled it out in a contested convention,” Cruz told Fox News in an interview released Wednesday morning. “That’s what conventions are for.”

Tuesday’s results were a reversal for Cruz, who performed well in four states that voted Saturday, winning two, Kansas and Maine, and emerging ahead of Trump in the day’s delegate haul.

Kasich’s third-place finish in Michigan, a blow after he predicted as late as Tuesday night that he would come in second, is a sign of potential trouble for him in Ohio because of the demographic similarity of the two states.

Kasich’s chief strategist, John Weaver, sought to make the case that the governor was in a good position as the nominating race moves away from the South.

“After March 15, more than 1,000 delegates will still be available, and the electoral map shifts significantly in our favor, with the delegate-rich states fitting Governor Kasich’s profile,” Weaver wrote in a strategy memo late Tuesday.

But even if Kasich wins Ohio and its 66 delegates, along with some of the others at stake on the same day in Illinois, Missouri and North Carolina, his chances of gaining a majority of 1,237 is close to a mathematical impossibility. Only 1,000 delegates will remain after March 15.

“His path to the nomination during regulation time, primary season, is narrow enough to be invisible,” said Joshua T. Putnam, a political science lecturer at the University of Georgia with an expertise in delegate selection. “His only path is to survive with some delegates into the convention.”

Similarly, Rubio is facing a daunting mathematical roadblock. In failing to reach 15 percent of the votes in Michigan and Mississippi, and 20 percent in Idaho, he was shut out of delegates entirely in the three states holding primaries Tuesday. He may have picked up as few as two in Hawaii.

Trump’s rivals seized on a new poll from The Wall Street Journal and NBC News on Tuesday showing a tight race among all four candidates in states that had not yet held primaries or caucuses. Trump was the favorite of 27 percent of likely Republican primary voters in those states. Cruz was favored by 25 percent, Kasich 24 percent and Rubio 23 percent.

The poll also suggested that if the race were to narrow to a one-on-one contest, Trump could be in trouble. In two-person matchups, all of Trump’s three rivals were preferred by voters.

“Next week will give us our first real clear indication,” Putnam said. “If Trump is shut out in Florida and Ohio, that portends a long battle in a race for a plurality rather than a majority.”

On Tuesday, Kasich said that if Trump had a plurality of delegates coming into the convention, but fewer than a majority, the Republican party should not assume he deserves the nomination.

“It’s like being in school and you know that a 90 is an A and you get to 88 and everybody else is below you,” he said. “We don’t grade on a curve when it comes to conventions.”

But Republicans would be playing with fire if Trump is leading the delegate race and is denied the nomination at a contested convention.

“It would tear the party in two,” Bennett said. “Whoever gave his sham acceptance speech would be doing it to a lot of empty chairs.”

© 2016 The New York Times Company