Sen. Marco Rubio, R-Florida, said Sunday that the Republican establishment "thought I needed to wait my turn or wait in line" to run for president, but he thought the situation in 2016 was too urgent to delay.
"I just felt that after seven years of Barack Obama, this was no time for patience. It was a time for action. And so I ran," he said in an interview on CBS' "Face the Nation" Sunday.
Rubio said his determination to run this cycle explains why his rivals, including fellow Sen. Ted Cruz of Texas and former Florida Gov. Jeb Bush - who was his political mentor - have spent millions of dollars attacking him. But he added that the donors who wrote huge checks for Bush's super PAC are probably "disappointed" that their candidate has performed so poorly in the election.
"In the end, this election is in God's hands, as everything is. And so we're going to do our very best. And we're confident about where that leads," he said.
Rubio called Cruz the frontrunner heading into the Iowa caucus, even though the latest Des Moines Register poll shows him trailing businessman Donald Trump by five percentage points. Rubio placed third in the poll with 15 percent support among likely Iowa caucus goers.
Cruz "has 10,000 volunteers on the ground. He has spent an exorbitant amount of time here...and has gotten every endorsement he wanted. So we know it's a tough hill to climb, but we feel very good about our campaign and very positive about what it means going into New Hampshire," Rubio said.
He plans to leave Iowa as soon as the caucus is over Monday evening to continue campaigning in New Hampshire.
Cruz, for his part, is calling Rubio the "Republican Obama" in a new television ad because of his work on the 2013 comprehensive Senate immigration legislation that included a pathway to citizenship for immigrants in the U.S. illegally. The ad also suggests that Rubio supported a cap-and-trade program to lower carbon emissions.
On "Face the Nation," Rubio called the attacks "kind of bizarre" since he opposes "virtually everything Barack Obama stands for."
"It's kind of strange that at the last minute, they've pivoted all their attacks against me. And disingenuous attacks," he said. He suggests the section of the ad about cap and trade was deceptively edited to make viewers believe he supported this program.
"This has already been lampooned and mocked for years because others have tried to do the same thing. So it's kind of a weird and strange last minute desperation attack. I really don't understand why. He's got such a strong organization here in Iowa. But it's all fine. We're going to be okay," Rubio said.
Later, he added, "People don't attack a candidate that has no chance to win."
He also continued his criticism of Cruz's immigration position, saying the Texas senator "portrays himself as some sort of purist" which is not true because he helped design former President George W. Bush's immigration plan and has flipped on several issues.
"When he was in the Senate, he talked about wanting to pass immigration reform, about bringing people out of the shadows, et cetera. He's not what he portrays himself to be," he said. "The lie is that Ted continues to try to portray himself as the only conservative in the race."
He said that's not a character attack, though - it's an attack on Cruz's record. Rubio said he has reversed course on support for doubling the number of green cards, boosting the availability of guest worker visas and birthright citizenship.
He also said that Cruz "goes around talking tough on China" but has defended a Chinese company that "stole an invention from an American, a Floridian, a constituent of mine," Rubio said. He said it all proves "incredible calculation" on Cruz's part.
"He goes to New York and raises millions of dollars and then goes to the rest of the country and attacks New York values. These are the things that over time people start to realize that there's a real calculation here politically. And it just catches up with you," he said.