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Story highlights

Marco Rubio apologized privately to Donald Trump in person for crude remarks he made about Trump's appearance

Rubio also admitted a series of mistakes that he says eventually bedeviled his campaign

Washington CNN —  

Marco Rubio apologized privately to Donald Trump in person backstage before a Republican debate for crude remarks he made about Trump’s appearance, the Florida senator said in an exclusive CNN interview.

Meditating on everything from Trump’s rise to his fractious relationship with Jeb Bush, Rubio revisited nearly every turn of his presidential run in an interview with CNN’s Jake Tapper that aired Sunday on “State of the Union.” The former presidential candidate, who has grudgingly said he will support Trump in November, also admitted a series of mistakes that he says eventually bedeviled his campaign.

Chief among those, Rubio has said, was belittling Trump for the size of his hands in the leadup to Super Tuesday, which he has publicly said he regrets. But Rubio went further when speaking with Tapper.

“I actually told Donald – one of the debates, I forget which one – I apologized to him for that,” Rubio said. “I said, ‘You know, I’m sorry that I said that. It’s not who I am and I shouldn’t have done it.’ I didn’t say it in front of the cameras, I didn’t want any political benefit.”

Rubio, who told Tapper that he would be willing to speak on Trump’s behalf at the convention, did signal some respect for the man he has sharply criticized, praising him as “the ultimate change agent” and that he may be developing “perhaps a more comprehensive approach” on some policy questions.

Rubio recommended that Trump not drastically alter his approach in the general election.

“I don’t think he should change if he’s been successful,” Rubio said when asked about Trump dredging up scandals of the 1990s to attack Hillary Clinton, which Rubio said he himself wouldn’t do. “I may not like that direction, but at this point, he won and this is the direction that he won on.”

Rubio also offered an assessment of his own political stumbles during his year as a presidential candidate. The Florida senator said his fundamental problem was that he “didn’t have a logical political base on which to build,” given former Florida Gov. Jeb Bush’s supremacy in Florida, especially among donors. That caused Rubio to spend an inordinate amount of time on private fundraising visits, he said.

The result was that Rubio was frequently criticized during the primary season for his light footprint in several primary states, including Iowa, where he finished a surprisingly strong third.

“The argument is, should we have picked a couple of states and said here’s where we’re going to lay a marker and win? Sure. That sounds great in hindsight,” he said. “Here’s the reality: If I had said that about Iowa and finished in third, that would have been the last night of my campaign.”

Rubio then hoped to finish second in New Hampshire, but was derailed by a disastrous debate performance at the hands of Chris Christie, who mocked him for clinging to memorized sound bites.

“I walked right into that trap,” Rubio said.

Had he finished second in the Granite State, Rubio said he believed he could’ve earned gold South Carolina.

Yet the governor that Rubio had the most complicated relationship with was Bush, his political mentor. The pair memorably clashed in a fall debate when Rubio beat back a Bush attack on his less-than-stellar Senate attendance record.

RELATED: Rubio: I’d ‘maybe’ run for re-election if my friend wasn’t

Bush did not endorse Rubio before the Florida primary, in which Rubio was pummeled and caused him to immediately end his bid. Rubio called the two weeks between Super Tuesday and the Florida primary on March 15 – when he was consistently being asked about the demise of his White House hopes – as the “toughest part of the campaign.”

“The negativity about our progress was so bad that a lot of voters, I think, concluded, you know, he’s not going to win, Trump is going to win,” Rubio told Tapper. “And that momentum really impacted Florida. I’m not sure there was anything we could have done at that stage about it, to change that trajectory.”

RELATED: Rubio says he’s going to the GOP convention

Rubio said that he and Bush have spoken a few times since the campaign concluded.

As for what’s next – assuming Rubio does not re-enter the race for his current Senate seat – the Florida senator again ruled out running for governor of the state in two years and reaffirmed his dream of serving as commissioner of the NFL. But Rubio said he expects to work in the private sector in some capacity.

“I’ll learn from this,” he said of his campaign, “and whether I run for president again one day or run for something else or do this in the business world, there are lessons I will take from this that will make me stronger and better as a result.”