Sen. Marco Rubio on Thursday opened the door a crack to staying in the Senate next year amid a concerted effort by his Republican colleagues to push him to run for re-election.

The Florida Republican’s decision could be crucial to keeping the Senate in Republican hands, given that none of the many Republicans running for his seat have Rubio’s name recognition or fundraising prowess in the pivotal battleground state.

After Rubio was approached by other senators, including Majority Whip John Cornyn of Texas, asking him to reconsider, he softened his oft-repeated declaration that he will be a private citizen come January.

Now, Rubio — who said he would not stand for Senate re-election when he announced his failed presidential bid — said it is “unlikely” he will change his mind before the Florida filing deadline on June 24. The state’s primary will be held Aug. 30.

Late Thursday, Rubio received more encouragement — from Donald Trump, the presumptive Republican presidential nominee who mocked Rubio as “Little Marco” during their primary race. “Poll data shows that @marcorubio does by far the best in holding onto his Senate seat in Florida. Important to keep the MAJORITY. Run Marco!” Trump.

“This is just something that happened today or what have you. For me, I need time to even talk to anybody about it, but my sense of it is nothing has changed in my thinking,” Rubio told reporters at the Capitol.

Cornyn said he was encouraged at Rubio softening his stance.

“To me that sounds like an opening,” he said. “That causes me to be hopeful.”

Rubio would clearly be the party’s strongest candidate, Cornyn said.

“It’s hard to get name ID in a state as large as Florida,” Cornyn noted. “It’s kind of like Texas, and you’re doubly hamstrung by the fact that the primary is late in August and there’s only so much you can do in a short period of time to turn that around. So he certainly would be the favored candidate, it seems to me.”

Cornyn predicted other efforts would be made to persuade Rubio.

“I wouldn’t be surprised to hear that Senator Rubio is being contacted by all sorts of people,” Cornyn said of the nascent effort to draft him to run. “I’m not aware of any specific plans. I’m just saying that there’s a lot at stake.”

Cornyn said nearly all of the Senate Republicans agree and want Rubio to run.

“I think it’s as close to universal as you can get around here,” he said.

Getting in this late presents some complications for Rubio, who would have to gear up his campaign apparatus and potentially face an ugly primary.

“Part of the reason why” it’s unlikely he’ll reconsider his decision, he told reporters, is that Florida Lt. Gov. Carlos Lopez-Cantera, a close friend, is seeking the seat. Rubio recently attended a fundraiser for Lopez-Cantera.

He declined to answer what he would do if Lopez-Cantera urged him to run, smiling and saying he doesn’t answer hypotheticals.

“He’s focused on his campaign and I think he’s doing well, you know, he’s a good friend and I think he’d be a good senator,” Rubio said.

Two House Republicans are also running for the nomination — David Jolly and Ron DeSantis.

Rubio did say voters have yet to focus on the race, and he slammed the Democrats running, Reps. Patrick Murphy and Alan Grayson.

“It’s not like the Democrats have the greatest candidate,” Rubio said. “One guy keeps exaggerating his biography and the other guy is a certified lunatic, so.”

Democrats, who need to win five seats to control the Senate outright, view Florida, a state President Barack Obama won twice, as a prime pickup opportunity.

(c) 2016, Bloomberg · Steven T. Dennis