Former President Donald Trump's allies are waging a behind-the-scenes battle to push Senate Minority Leader Mitch McConnell (R-KY), the only major Republican leader who has not yet endorsed Trump's bid for re-election, to do so, reported The New York Times on Monday — in the face of years of bad blood between the two of them that has rifted any sort of professional relationship.

"Assuming it happens, Mr. McConnell’s endorsement of Mr. Trump would have enormous symbolic value to the former president, giving him the embrace of the last holdout of Republican power whose rejection of him represents the final patch of unconquered territory in Mr. Trump’s march to the party’s 2024 presidential nomination," reported Jonathan Swan, Maggie Haberman, and Shane Goldmacher. "The support of Mr. McConnell ... would also carry huge value in signaling to an entire class of donors and Trump-resistant Republican elites that it’s acceptable to get behind the party’s expected nominee — no matter their misgivings. This is no small thing, given that Mr. Trump has been forced to spend more than $50 million already on legal bills, and the groups supporting him are expected to be vastly outspent by President Biden’s operation."

"The secretive conversations between the Trump and McConnell camps have been happening between key advisers to both men who have known and worked with each other for more than 20 years: Chris LaCivita, a top campaign adviser to Mr. Trump, and Josh Holmes, a confidant and longtime political strategist for Mr. McConnell," the report continued. "Since around the time of the Iowa caucuses last month, Mr. LaCivita and Mr. Holmes started making more of a concerted effort to trade information — particularly about Mr. Trump’s Senate endorsements — and to create an opening for a more productive working relationship ... By late January, Mr. Trump had told people close to him that he expected Mr. McConnell would endorse him."

Trump and McConnell used to be firm allies, with the latter delivering Trump a tax cut bill and a large number of far-right judicial confirmations. However, they have been on the outs ever since McConnell criticized Trump's role in the Jan. 6 attack on the Capitol, even though McConnell ultimately voted to exonerate him in the Senate trial.

The two Republicans have not spoken to each other since December 2020, the report noted, and furthermore, Trump has repeatedly and publicly attacked McConnell, blaming him for inaction on his policies and even suggesting that he will cut ties with the Senate leader if he wins office.

All of this comes as Trump won a narrow but clear victory against his final remaining rival, former South Carolina Gov. Nikki Haley, in her own state, and despite the multiple criminal indictments proceeding against him, appears all but certain to be the nominee. McConnell has already made clear he will back whoever wins the nomination.