If Ted Cruz is to slow Donald Trump’s march to the Republican presidential nomination by closing a gap in polls and defeating the billionaire in Indiana’s primary on Tuesday, he’ll need conservatives such as Catherine Lanctot of Indianapolis.

Lanctot, 59, has been making phone calls to voters at Cruz’s Indianapolis office most days during the past week when she wasn’t home-schooling her two youngest daughters. The nomination fights are usually over by the time Indiana votes, and Lanctot said she’s making the most of the state’s pivotal role this year to help Cruz, who she sees as the most principled conservative in the race.

“We don’t have the biggest delegate count, we’re not the first to vote in a primary, and we’ll just sit here frustrated,” Lanctot said of past presidential nominating contests. “So we had to put the walk behind the talk this time and say, ‘We have no excuse.”’

Indiana has become essentially a last stand for Cruz and the forces trying to prevent Trump from securing the party’s nomination on a first ballot at its convention in July, and the urgency shows. At the start of the week, Cruz announced an unconventional deal with Ohio Gov. John Kasich to have Kasich cede Indiana and Cruz not campaign in Oregon and New Mexico. Cruz then named former rival Carly Fiorina as his running mate should he get the nomination.

And with Trump leading in several polls-a Wall Street Journal/NBC News/Marist poll on Sunday showed Trump 15 percentage points ahead of Cruz-the Texas senator is counting on his data-driven grassroots organization to counter Trump’s appeal to displaced middle-class workers and other disaffected voters. Cruz also is tapping a network of social and religious conservatives in Indiana that is naturally aligned with his candidacy and has been active in legislative fights in the state over religious liberty and gay rights.

“Without it, it’s a Trump state,” said John Hammond, the state’s national Republican committeeman and a party delegate. “It is a very strong base that is used to being mobilized.”

Still, while Cruz’s campaign said it has five offices in Indiana, about a dozen paid staff and more than 3,000 volunteers “in a sign that grassroots conservatives are rising up and coalescing behind Ted,” Trump has four offices and 40 paid staff also making calls and knocking on doors, said campaign manager Corey Lewandowski. He said opponents ignore Trump’s ground game at their peril, and the results are obvious in the states he has dominated-including South Carolina and Alabama, where he won over evangelicals.

“It’s the same narrative that they always perpetuate, which is, ‘We have the greatest ground game ever,’ and the truth be told, that’s not what happens because the voters are rejecting Ted Cruz,” Lewandowski said. “Donald Trump is the presumptive nominee right now, and a win in Indiana will continue to remind everyone that it’s time to unite the party behind Donald Trump.”

Speaking at packed stadium of 15,000 in Fort Wayne on Sunday, Trump said he didn’t want to take the race for granted. Outside, an airplane carried a banner that read, “Seal the deal, Indiana. Vote Trump.”

“Forget the polls, pretend we’re losing-we’re not, but pretend. The bigger we win by the better,” Trump said.

Aside from a trip to California on Saturday to speak at the state party’s convention, Cruz has campaigned hard in Indiana, holding daily rallies and shaking hands at pancake restaurants and candy stores in small towns across the state. He has tested a number of messages, including being glad the race has moved back to friendlier turf, that the state’s voters have a chance to stop Trump, that he’s the only true conservative in the race, and the mainstream media and “New York power brokers” and lobbyists want the race to be over.

“This entire political process has conspired to put the State of Indiana in the position to stand up and speak the voice of sanity,” Cruz said during a rally on Sunday night in La Porte, begging people to get their friends, neighbors and family to vote to sway the race in his favor. “I could not be happier that this election is coming down to the Hoosier State, to Midwestern common sense, the good judgment of the men and women in this great state.”

Indiana will award 57 delegates in the Republican primary, 30 to the statewide winner and three in each of the state’s nine congressional districts. Trump has 996 of the 1,237 delegates needed for the nomination, according to an Associated Press tally, and with both Cruz and Kasich mathematically unable to reach that number before the convention, they’re hoping to force multiple ballots in Cleveland.

Even before the campaign calendar turned to the Hoosier State, Ron Johnson, executive director of the Indiana Pastors Alliance, said he arranged several speaking engagements in churches across the state for Rafael Cruz, the senator’s father.

The campaign is also using social media and activists to recruit volunteers, said Monica Boyer, a tea party leader from Warsaw, Indiana, who was active in the effort to defeat six-term Senator Richard Lugar in the 2012 Republican primary.

Preaching on Sunday at the Living Stones Church in Crown Point where he is senior pastor, Johnson did not mention Cruz by name or endorse him. But he’s personally backing Cruz, and he told about 100 church members at the 8:30 a.m. service that there’s only one candidate who stands with them on non-negotiable issues of anti-abortion, gay marriage and protecting religious liberty.

“I encourage you, get out this Tuesday, May the 3rd, and make your voice heard,” Johnson told the congregation. “Indiana literally has an opportunity to turn the whole course of the direction for this election.”

Boyer said Friday’s endorsement of Cruz by Indiana Governor Mike Pence also could help motivate social conservatives as well, though Pence, who is locked in a tough re-election fight this year, also praised Trump and said he’ll back whoever emerges as the nominee.

On Saturday, Cruz’s headquarters in Indianapolis was jammed with people using the 70 phones on five long tables to call voters and teams of canvassers heading out to knock on doors. Volunteers used an application on their mobile devices that provided the houses of Republican voters targeted by the campaigns.

Brian Higgins, a volunteer who worked for Cruz in Iowa, South Carolina and in Wisconsin, where Cruz tapped a network of conservative voters and talk radio with the backing of Governor Scott Walker to defeat Trump, said he’s feeling more optimistic about Indiana as the primary approaches. Cruz had more offices in Wisconsin, but the same data-driven organization in place in Indiana, he said.

David Flynn, 74, a retired physicist from the Salt Lake City area, came to knock on doors in Indiana because he knows the stakes, he said.

“If he wins, it appears to me that we’re more assured of going to an open convention,” Flynn said. Otherwise, the nomination of Trump is more likely, which “scares me to death,” he said.

Through April 26, Trump had run more broadcast television spots in Indiana than Cruz, according to data from Kantar Media’s CMAG. The front-runner had aired 1,249 spots in the state, while Cruz had run 639.

The air war, however, favors Cruz, once outside groups either supporting him or opposing Trump are factored in. Trusted Leadership PAC, Club for Growth Action and Our Principles PAC have run a combined total of 1,227 spots in the state, the CMAG data shows.

By comparison, Trump ran just 457 spots in Wisconsin prior to his April 5 loss there to Cruz. The Texan, along with the same pro-Cruz and anti-Trump groups that have aired ads in Indiana, ran 1,439 spots on Wisconsin broadcast television.

Even so, Trump supporters say Indiana is not Wisconsin. At Trump’s office in a Carmel strip mall north of Indianapolis, about 25 volunteers worked the phones on Saturday and a steady stream of people came in for Trump yard signs. Scott Peterson of Carmel took a photo of his 10 year-old daughters next to a life-size cardboard cutout of Trump.

Sally Farris, 72, a retired executive assistant who has been coming to the Trump office in Carmel twice a day to call voters, said whatever Cruz volunteers and social conservatives are doing on behalf of Cruz can’t match the passion that voters have for Trump.

“Indiana is very conservative,” Farris said. “But his mannerisms and what he is saying I think has changed a lot of people. They’re seeing that, ‘OK, this guy is for real.”’

Megan Robertson, a Republican consultant in Indianapolis who opposed the push by social conservatives for a state constitutional amendment in Indiana banning gay marriage in 2014, said the deal that Kasich struck with Cruz could actually help Trump. The Wall Street Journal/NBC News/Marist poll showed that 58 percent of likely Republican primary voters in Indiana disapproved of the deal. Robertson said she also doubts Cruz naming Fiorina will help.

“The whole thing smacks of being pandered to,” Robertson said. “I just think we’re all so disenchanted with the process that everyone sees right through it at this point.”

(c) 2016, Bloomberg · Mark Niquette