Republican presidential candidate, Sen. Marco Rubio, R-Fla., appears with Kansas Gov. Sam Brownback at a campaign rally in Topeka, Kan., Friday, March 4, 2016. (AP Photo/Paul Sancya)

Topeka ? U.S. Sen. Marco Rubio, R-Florida, brought his struggling presidential campaign to Kansas on Friday, hoping a string of endorsements from the state’s Republican elite would help him notch his first win by taking the state’s GOP caucus Saturday.

A crowd of about 300 people greeted Rubio outside an airplane hangar at Forbes Field in Topeka, where he was flanked by Gov. Sam Brownback, U.S. Sen. Pat Roberts and his two state co-chairs, State Sen. Terry Bruce of Hutchinson and Rep. Erin Davis of Olathe.

In a 30-minute speech that touched on a wide range of topics — from foreign policy and the military, to health care and his own family history as the son of Cuban immigrants — Rubio took aim at GOP frontrunner Donald Trump by insisting Rubio is the only candidate in the race who can unite the Republican Party.

“Because the truth is, 65 percent of people who have already voted don’t want him as our nominee. And if our party is fractured and splintered, we can’t win,” Rubio said.

Republican presidential candidate Marco Rubio signs autographs following a rally in Topeka that drew about 300 people. Rubio is barnstorming Kansas the day before the state's GOP presidential caucuses.

So far in the campaign, he has been vying with U.S. Sen. Ted Cruz, R-Texas, for second place in the GOP race, with both men trailing Trump by wide margins.

But Rubio hopes to turn that around in the Kansas caucuses Saturday, and he’s hoping the state’s top elected Republicans can help him do that, if not by winning the state outright, then at least by making a strong showing.

“I can tell you we’ll leave here tomorrow with delegates, and this has now become a delegate fight to see who can get to 1,237 first,” he said. “And if not, who can go into the convention with the highest number of delegates.”

Republican delegates chosen in the Kansas caucuses will be divided proportionately among all the candidates who get at least 10 percent of the vote.

One of the big questions in Kansas, though, is whether, in a year dominated by anti-establishment sentiment, Rubio’s string of endorsements from top elected GOP leaders in the state will help or hurt his campaign, especially given a recent Fort Hays State University poll showing Brownback and the Kansas Legislature with lower job approval ratings than President Barack Obama.

“In any typical election year, all of those folks lining up would indicate, there’s the momentum. Not in 2016,” said FHSU political science professor Chapman Rackaway. “Trump’s momentum is based on the idea that insider politics is what got us into trouble in the first place.”

According to the FHSU poll, the GOP race in Kansas was still wide open in the week leading up to the caucuses, with 39 percent of Republican respondents saying they were still undecided. Trump was named by 26 percent, followed by Cruz at 14 percent and Rubio at 13 percent.

But Rackaway said the race may be tightening as those undecided voters start making up their minds. One indicator of that, he said, was Trump’s announcement Friday that he was canceling a scheduled appearance at the Conservative Political Action Convention, or CPAC, in Washington and traveling to Wichita to campaign Saturday morning, just before the caucuses open.