But heading into Tuesday's Nevada Republican caucuses, Rubio's best case scenario is a second place finish to Donald Trump. Again.
"It would take a miracle for him to finish any higher than second," said veteran Nevada journalist Jon Ralston. "He's got a very, very good ground game run by some very smart people. ... They know what they're doing."
Polling in Nevada is notoriously unpredictable. But CNN's most recent poll in the Silver State put Trump way ahead of the field, with Rubio in a tenuous second place.
In the February 17 poll, which carried a margin of error of 6.5 percentage points, Trump was backed by 45% of likely GOP caucusgoers, Rubio was at 19% and Texas Sen. Ted Cruz was at 17%. Ben Carson and Ohio Gov. John Kasich trailed in the single digits.
Rubio said he feels good about the state and "confident" about the race, but doesn't take it for granted because of his connection to it.
"Obviously I have ties to Las Vegas that run deep given my time growing up here. ... but I'm not sure that's going to be enough to simply be a determinate factor in the caucus," Rubio said Monday in Nevada. "I think it's going to be like every other candidate that's coming in, we're going to have to compete hard."
Rubio would seem to be very well suited to Nevada. For his ground game, he hired Mike Slanker and Jeremy Hughes, veteran political operatives in the state who have worked with virtually every successful Republican elected official, including the rising GOP star Gov. Brian Sandoval.
Rubio's state chairman is Lt. Gov. Mark Hutchison, another top Nevada Republican and one of the state's most prominent Mormons.
In recent days, Rubio has picked up the support of Nevada Sen. Dean Heller, who previously backed Bush, and Nevada Reps. Mark Amodei and Cresent Hardy. Utah Rep. Jason Chaffetz, who endorsed Rubio a few weeks ago and is a Mormon, has been deployed in the state ahead of Tuesday's caucuses as well. Utah Sen. Orrin Hatch, also Mormon, told CNN's Manu Raju on Monday that he is also backing the Florida senator.
Rubio used a similar strategy of prominent endorsements in South Carolina, where he narrowly beat Ted Cruz for the second place spot in Saturday's primary.
But in Nevada, he can also highlight his local roots. Rubio lived in Las Vegas for a stretch of his childhood, from third to eighth grade, a fact he often mentions in his family-centric stump speech. He is also the son of Cuban immigrants -- a fact he highlights in this state, which is almost 30% Latino.
The Florida senator has been making inroads with the state's key Mormon population, in part through his endorsers. Rubio's family also briefly joined the Mormon church when he was a child, giving him familiarity with the community. In the 2012 GOP Nevada caucus, 25% of the electorate were Mormons according to entrance polls
, brought out in part by Mormon candidate Mitt Romney.
"I think that Nevada is well-suited for Marco Rubio's strength, which is he appeals to a very broad section of the electorate," Hutchison said. "We're not focused on one particular group. But I will say as a member of the church, Marco Rubio is very appealing to members of the Mormon faith. He talks a lot of the importance of family and how government cannot replace family. We believe very deeply that family is the most important unit in society."
Alongside his conversations about religion, Rubio has been sprinkling talk of eminent domain into his stump speeches in recent weeks, a key issue for conservatives in a state heavy on federal lands.
Rubio's campaign strategy is built on staying in the delegate race until the other candidates drop out and he can consolidate their support. Bush bowed out Saturday out after a dismal result in South Carolina. He has yet to endorse and a handful of his donors and supporters have publicly joined the Rubio camp so far, but the campaign expects to pick up much of his support going forward.
Nevada will be Rubio's first opportunity to prove he can consolidate the establishment lane of the party, though Bush had only been polling at 1% in the Silver State and Kasich has pledged to stay in the race through early March, at least.
Anything can happen in Nevada's caucus, experts say. Turnout is notoriously low and the evening caucus set-up is confusing, introducing unpredictability and making organization all the more important.
"It's all about the ground game and all about the grassroots," Hutchison said. "We've been focused on that."