MANCHESTER, N.H. – John Kasich is preparing for the biggest day of his life.

On Tuesday, New Hampshire voters will cast primary ballots that determine the future of his presidential campaign.

If he wins or places in the top tier, he’ll have strong reasons to continue in the race for the Republican nomination. If he falls behind his closest rivals, he’ll face pressure to drop out, and his hope of serving as the nation’s next president will evaporate.

On Monday, Kasich stood on the cusp of something – and knew it.

“If I ramble a little bit, forgive me. This is my last town hall,” Kasich, fighting a cold, told voters in Manchester. His tone turned contemplative, and throughout the day he told old stories about his late parents, his wife and a random guy he met at a gas station, who inspired him to push to balance the budget as a congressman.

“I want to bring out the best of what we are as Americans,” Kasich said in Windham, asking the state’s famously undecided voters to propel his candidacy.

How undecided?

Mark Croteau, a Nashua truck driver, was making phone calls for Carly Fiorina at her campaign office on Saturday. But that didn't stop him from checking out Marco Rubio Saturday morning and Jeb Bush Sunday. He decided on Bush, but thought he'd give Kasich one more shot Monday morning -- and spent the rest of the day attending each of Kasich's events and putting up yard signs for the governor.

"Back in the summer, he was my favorite candidate. But he was polling so low, I didn't think I wanted to waste my vote," Croteau said. Now, Kasich is performing better. And, Croteau said, "he seems like he can work with both parties and get things done."

On Monday night, as many as 150 volunteers rallied with Kasich in a snowstorm outside Robie's Country Store in Hooksett.

"How could you possibly say thanks?" Kasich asked.

"Win!" a few people shouted.

"We will win!" Kasich whooped back.

Still, a win in New Hampshire would be an upset. Even with a strong showing, Kasich faces hurdles as he continues his campaign.

These factors will determine whether Kasich succeeds Tuesday

How polls say he will do

Donald Trump continues to hold a 15- to 20-percentage-point lead in New Hampshire polls, with Kasich still in a tight battle for second place.

After his better-than-expected finish in Iowa, Rubio had pulled into second by himself, but his small lead over Kasich and other rivals appears to have evaporated after Rubio’s rough debate performance Saturday. And Kasich’s momentum, which started in early January, appears to have continued, helped in part by his strong debate performance Saturday.

Beyond questions about Rubio’s strength, the main wild card involves the frontrunner. Will Trump struggle, as he did in Iowa, to turn supporters out to vote? Will his support wane now that he has finished in second in one contest? If the latter takes place, other candidates, ranging from Kasich to conservative Sen. Ted Cruz, could pick up some of Trump’s voters.