Perry encouraged supporters to keep the faith in his national aspirations as his advisers cast the coming contest in South Carolina as the first real test of his presidential campaign. Before Iowans met at churches and schools to signal their preferences, Perry was downplaying the role of the traditional lead-off states.
"The idea that one or two states is going to decide who the next nominee for the Republican Party is just, you know, that's not reality," Perry told CNN before the caucuses began.
He also signaled that he saw the contest to oppose President Barack Obama as a two-man race between himself and Mitt Romney, the former Massachusetts governor.
"Mitt Romney has got a real problem when it comes to consistency," Perry said. "Those folks in South Carolina, I can promise you, they're not going to buy a pig in a poke, so to speak, and a Massachusetts governor that put individual mandates in place that Obama took as the model to create Obamacare is not going to sell in South Carolina."
Romney signed into law a health overhaul that was a model for Obama's national legislation. The law's requirement to purchase health insurance has been a sore point among conservatives but has not to this point proved prohibitive to Romney's White House dreams.
Perry began the day with a visit to volunteers, hoping to buoy their enthusiasm in the face of public and private polling that indicated they would be sorely disappointed when the results are announced Tuesday night.
The Texas governor and former Air Force pilot compared caucus day to a military campaign.
"This is Concord. This is Omaha Beach," he said. "This is going up the hill, realizing that the battle is worthy. This is about sacrifice. Every man and woman has sacrificed your time, your treasure, your reputation.
"But you're doing it out of love for this country," he continued. "That is what gets us up every day, gives us the courage, the fortitude, the focus to go do what we have done for the last almost six months."
Perry entered the race in August to great fanfare but, faced with a compressed timeline and saddled with weak performances in televised debates, proved unable to sustain the sizzle.
On Tuesday, he urged supporters to stick with him and pointed to his 16-year courtship of his wife, Anita. At the same time, his advisers began casting the Iowa contest as a practice run for states to come, specifically the South's first primary, in South Carolina on Jan. 21.
"She was a hard sell, folks. If it's 16 years to talk her into marrying me, then however (many) months we need to do to talk Americans into our vision, that's what we're going to do," Perry said, suggesting an early exit from the campaign was unlikely.
At a town hall-style meeting with an insurance company's employees, he again signaled that he understood his challenges and called the caucuses "the first day of this process."
"I don't get confused that this is a marathon," he said. "It is going to go on for some time."
Unlike a day before, he did not predict a victory.
The final Des Moines Register poll, released Saturday, showed Perry at 11 percent and trailing four rivals with Romney and Ron Paul in a dead heat.
The Texas governor made a last-minute push Tuesday to avoid an embarrassing finish. At his first town hall-style meeting, he said he would push for amendments to the Constitution that would ban deficit spending, would relegate Congress to a part-time role and do away with lifetime appointments of federal judges. After a sometimes rambling 25-minute speech, no one in the audience rushed to ask him questions.
To fill the gap, Perry awkwardly hummed the theme song from the game show "Jeopardy!"
Perry's team planned events in South Carolina for Wednesday and hoped a jumbled pecking order would emerge from Iowa's caucuses.
"We didn't come into this race lightly. We came into it with both feet on the ground," Anita Perry told supporters in a morning pep talk that reflected the dour mood. "You know what we've learned through this? Loyalty and friends. That's what gets you through it."