Two Republican sources told HuffPo that Romney had hesitated to endorse Rubio while Jeb Bush was still in the presidential race, but that Bush’s campaign suspension on Saturday opened the way for an endorsement. In doing so, Romney would give Rubio his most high-profile endorsement yet.

GOP Faces Divergent Paths After South Carolina

Rubio refuted the report on CNN’s State of the Union Sunday morning, telling host Jake Tapper:

That report is false. I have no reason to believe he’s anywhere near endorsing…We’d love to have his endorsement. We’d love to have the help of everyone because we’ve got to bring the Republican party together….We’d love to have his endorsement, but there’s nothing forthcoming.

Marco Rubio Celebrates Strong Finish at Iowa Caucus:

Reporters from The New York Times and The Washington Post wrote on Twitter on Sunday that they did not believe an endorsement was imminent.

Heard same from a few people > https://t.co/GzTAFJ78Jb

— Maggie Haberman (@maggieNYT) February 21, 2016

On Rubio endorsement news, I was just told by a person familiar with Romney's current thinking that nothing has changed, no endorsement yet.

— Philip Rucker (@PhilipRucker) February 21, 2016

Romney endorsement or no, the Republican establishment seems to be coalescing around Rubio as a nominee. According to FiveThirtyEight, Rubio’s pace of endorsements has quickened since the Iowa caucuses; just this past week, he netted endorsements from Governors Nikki Haley of South Carolina and Sam Brownback of Kansas. And in the wake of Bush’s exit from the race, Reuters reports that many of his donors have already turned to Rubio as their next best bet.

Rubio won 22.5% of votes in the South Carolina primary Saturday—a full 10 percentage points behind first-place finisher Donald Trump.