Ted Cruz has described Tuesday’s Indiana primary as “the one thing that stands between us and plunging over the cliff.” The Texas senator and others trying to block Donald Trump from the Republican presidential nomination may be about to fall in.

The outcome in Indiana, where polls began to open at 6 a.m. Eastern time and will finish closing at 7 p.m., could yield a deciding moment as the race enters the home stretch.

The voting comes as Republican establishment forces appear increasingly resigned to the likelihood of Trump as their nominee, while the ragtag coalition of donors and others that comprise the “stop Trump” movement is making what would seem to be its last stand.

A Cruz loss could make the billionaire all but unstoppable in his quest to win the 1,237 delegates needed for the nomination, while a Trump defeat could rekindle the prospect of a contested Republican National Convention in July.

“The Cruz forces are the most well-organized in conventional political tactics, but in a year that defies convention at every step, the Trump phenomenon of mass rallies and digital media seem to have taken hold,” said John Hammond, a Republican National Committee member from Indiana who has not endorsed a presidential candidate. “The demographic in the Hoosier State leans toward Trump.”

Indiana polls show Trump with a double-digit lead over Cruz and Ohio Gov. John Kasich, while the Democratic race between Hillary Clinton and Senator Bernie Sanders is much closer.

Hammond said it’s too soon to say Trump’s nomination is inevitable. “But there is a growing chorus of national Republican realists and strategists who think he can’t be stopped,” he said. “They are filled with anxiety by what that outcome portends for the result in November against Clinton.”

Both Trump and Cruz spent most of the past week in the state, with Trump headlining two rallies there Monday. His message has focused heavily on manufacturing losses, including 1,400 jobs at a Carrier Corp. plant in Indianapolis.

“If we win Indiana, it’s over,” Trump said in Carmel, a suburb north of Indianapolis. “They have no path, whereas I have a very easy path.”

The real estate mogul also reveled in how he’s helped eliminate candidates from a primary field that once featured 17, including Wisconsin Governor Scott Walker and former Florida Governor Jeb Bush. “Senators, governors, top people, smart people, 17, boom, boom, Walker gone, this one gone, Bush gone-low energy-Bush gone, all gone,” Trump said.

The front-runner is scheduled to appear with his supporters at Trump Tower in Manhattan on Tuesday evening, as he’s done after primary wins in the last two weeks.

Trump has been on a roll since landslide victories in New York on April 19 and in five other Northeast states a week ago. If Cruz can’t break that streak, it could make it nearly impossible to slow Trump’s momentum in the remaining nine Republican contests that conclude June 7 with California, New Jersey, and three other states.

Cruz’s underdog status comes even after he’s tried a series of headline-grabbing moves to try to shake up the race. He’s criticized Trump for receiving the endorsement of “convicted rapist” Mike Tyson, who served prison time after the champion boxer was found guilty of a sexual attack on a Miss Black America contestant in an Indianapolis hotel room in 1991.

Other Cruz attempts to alter the race’s trajectory included a multi-state non-compete agreement with Kasich, naming former Hewlett-Packard chief executive Carly Fiorina as his running mate.

Indiana’s social-conservative leanings offered Cruz potentially fertile ground, but his pact with Kasich to have the Ohio governor avoid campaigning there proved unpopular with voters. He also called a basketball hoop a “ring,” a major gaffe in a place where the sport is part of the state’s fabric.

In the closing days of the campaign, Cruz received a less-than-full-throated endorsement from Indiana Governor Mike Pence, who praised Trump at the same time. Trump has the backing of former Indiana University basketball coaching legend Bobby Knight, as well as former Notre Dame football coach Lou Holtz.

Indiana will award 57 delegates, the biggest remaining cache other than California among the remaining contests. The statewide winner will get 30, with each of nine congressional districts also awarding three each to the victor there.

An NBC News/Wall Street Journal/Marist poll released Sunday showed Trump ahead of Cruz in Indiana by 15 percentage points. In the Democratic race, the poll had Clinton leading Sanders 50 percent to 46 percent.

Indiana holds what’s called an “open” presidential primary. That could boost Trump, who has shown greater strength in states where independents and Democrats can cross over to vote for him.

Cruz barnstormed Indiana on the final day before voting, holding two rallies, making three campaign stops and sending his wife and Fiorina to five other locations.

“The entire country is looking to Indiana and really, depending on Indiana, to pull us back from this cliff,” Cruz told reporters after greeting patrons at the Bravo Café in Osceola.

“The polls have been all over the map,” he told another media gaggle later in Fort Wayne. “This race is effectively tied in the state of Indiana. It is neck-and-neck and it depends on turnout.”

Asked if he still has a path if he loses Tuesday-and whether he would leave the race before the convention in July-Cruz said he still views the race as a marathon not yet done. “As long as we have a viable path to victory, I am competing to the end,” he said in Osceola.

The Texas senator said the Republican Party “will have failed the voters” if the choice in the general election is between Trump and Clinton, who he called “two rich, New York big-government liberals.”

Oran Richards, 80, a retired carpet cleaner from Elkhart who backs Cruz, said he’s struggling to remain optimistic.

“I hope he wins, and I’m concerned that he just might not,” Richards said. “I think a lot of people vote on emotions, and they’re angry about a lot of things that have gone on in the country. They want somebody who’s going to come galloping to the rescue.”

In a show of confidence about her standing in Indiana, Clinton on Monday started a two-day tour of West Virginia and Kentucky, which hold primaries on May 10 and May 17. Sanders campaigned in Indiana, in hopes of an upset win to bolster his argument for continuing his long-shot campaign.

Before Tuesday’s voting, Trump led the delegate race with 996, followed by Cruz at 565 and Kasich at 153. Clinton had 2,165 of the 2,383 delegates and superdelegates needed to win, compared to 1,357 for the Vermont senator.

(c) 2016, Bloomberg · John McCormick