SIOUX CENTER, Iowa — Former Florida Gov. Jeb Bush made his closing pitch to Iowan caucus-goers a contrast with Democratic presidential candidate Hillary Clinton rather than his Republican rivals.

"I can take it to Hillary Clinton because my life is a open book, her life is a closed book. Her life is one of mistrust, of never actually telling the truth when it's important to do it," Bush said. "The only way we beat Hillary Clinton is two things: one, go at her right away, take it to her, be strong, and be transparent so that the Hillary Clinton hit machine doesn't go after you. And number two, campaign with your arms wide open with a hopeful optimistic agenda."

Minutes after Bush's speech was scheduled to begin, more and more chairs had to be added at Dordt College's campus center to accommodate the swelling crowd. But many in attendance told the Washington Examiner they remain undecided three days before heading to the Republican caucus.

The undecided voters at Bush's event seemed impressed by the governor's performance, but no closer to making up their minds. Linda Steeg, an undecided Iowa resident, told the Examiner her decision will come down to the candidates' positions on healthcare and added that she was pleasantly surprised by Bush's performance."I think he was a lot more articulate than I expected," Steeg said, "just from listening to clips of him on the news."

Other undecideds listed issues of life and the candidates' behavior as chief among their concerns heading into Monday's caucus. Republican Congressman Adam Kinzinger, who traveled from his neighboring state of Illinois to stump for Bush, told the Examiner that it would be tough for Bush to win Iowa but he said the campaign remains optimistic that the governor will ouperform all expectations.

"This is my first Iowa experience, but there's a lot of energy and a lot of people that are growing to respect not just the bloviating of the cycle but of the honesty of Jeb Bush," Kinzinger said. "Look you had some polls showing he was going to come in dead last at one point. Today, you may see him well beat former top runners [in Iowa]."

Bush has also relied on his famous family to make his pitch in the final days before Iowans cast their ballots — including a TV ad featuring his mother — and two of Bush's children traveled with the governor on Friday. The company line around Bush appears to be that he will "exceed expectations," with actual predictions hard to come by. But the governor told the crowd in northwestern Iowa that he has faith in them to make the right choice.

"If you want to change the course of a political campaign, wow you're living in Iowa," Bush told the crowd. "And I trust you because you've kicked the tires, you've challenged the candidates. You get to see all of them."