New York billionaire Donald Trump expects Republican primary voters who cast ballots on Tuesday in Indiana to make him unstoppable in his march toward the party's presidential nomination.
"If we win Indiana, it's over," Trump told a cheering crowd in Terre Haute, Indiana, on the eve of the vote.
The blunt-spoken real estate mogul holds a double-digit polling lead over US Senator Ted Cruz of Texas, who has been campaigning in the Midwestern state almost nonstop since mid-April. Cruz has trumpeted Indiana, one of the last big states left in the fight to get onto the Nov. 8 presidential ballot, as his golden moment to stop Trump and force a brokered nomination at the party's July convention. But it appears to be shaping up as his Waterloo.
Fresh off a sweep of five Northeastern states last week, Trump wants a win in Indiana to put him within reach of the 1,237 delegates required to lock up the Republican nomination before the convention.
Trump now has 996 delegates, compared with 565 for Cruz and 153 for Ohio Governor John Kasich, according to The Associated Press. Another 57 delegates are up for grabs in Indiana, a state that has voted Republican in nine of the last 10 presidential elections.
Top Trump aide Corey Lewandowski told CNN on Tuesday the campaign expected to win more than required number of delegates - 1,300 to 1,400.
Cruz vowed on Monday to "compete to the end" but a loss in Indiana would be particularly crushing for the senator, who has argued that his brand of religious conservatism is a natural draw for heartland Republicans. He won the endorsement of conservative Indiana Governor Mike Pence.
Cruz had hoped for smoother sailing in Indiana after he and John Kasich reached a "stop-Trump" deal in which Kasich would steer clear of the state while Cruz would do likewise in Oregon and New Mexico.
But the waters are looking choppier for Cruz, with the senator losing considerable ground against Trump in opinion polls as voting has neared.
Cruz last week also announced his choice for a prospective vice president, the former presidential contender and Hewlett Packard Chief Executive Carly Fiorina, during an event in Indiana that some criticised as premature.
Trump has drawn both passionate support and vitriolic condemnation with his stands on immigration and national security - including a call to build a 1,000-mile wall along the Mexican border that he says Mexico would pay for and a bid to temporarily ban Muslims from entering the country.
Julie Blackwell Chase, a clerk treasurer in the town of Bedford in southern Indiana, said she voted early for Trump in part because she appreciated his willingness to break with conventional politics. "We need new blood," she said.
The outcome in Indiana may ride on the votes of evangelical Christians after Trump offered praise for Planned Parenthood family clinics and signaled support for gay and transgender rights - views that rankled some Christian conservatives.
Clark County Sheriff Jamey Noel, chair of the county's Republican Party, said he is voting for Cruz.
"Traditional Republicans and Republicans who understand how we elect our president, or pretty much everyone who's conservative, likes Cruz," he said.
Jeff Cardwell, chairman of the state's Republican Party, said Tuesday's primary marked an exciting day in Indiana politics, mainly because White House nominations are usually locked up by this late in the election cycle.
"This is the first time in my lifetime where Indiana has really had an opportunity to make a difference," said.
Indiana has the second-largest delegate haul of the 10 states remaining in the 2016 Republican nominating contest, behind California, which holds its primary on June 7.
On the Democratic side, front-runner Hillary Clinton holds a more than 6 percentage point lead over challenger Bernie Sanders, a US senator from Vermont, according to an average of recent polls compiled by Real Clear Politics.