President Donald Trump speaks to reporters at Trump National Golf Club in Bedminister, N.J., Thursday, Aug. 10, 2017. The president raised the possibility that Majority Leader Mitch McConnell should step down if he can't muscle health care and other legislation through the Senate, taking an extraordinary swipe at the man with the most power to steer the White House agenda through the chamber.  (AP Photo/Evan Vucci)
President Donald Trump speaks to reporters at Trump National Golf Club in Bedminister, N.J., Thursday, Aug. 10, 2017. The president raised the possibility that Majority Leader Mitch McConnell should step down if he can't muscle health care and other legislation through the Senate, taking an extraordinary swipe at the man with the most power to steer the White House agenda through the chamber. (AP Photo/Evan Vucci) Credit: Evan Vucci

President Donald Trump aimed a fresh barrage of criticism at Senate Majority Leader Mitch McConnell on Thursday, escalating an extraordinary fight with a key Republican leader that could undermine the party’s ability to regroup and pass shared legislative priorities this fall.

In a series of demeaning tweets and public statements, Trump blamed the Kentucky Republican, who remains popular among GOP senators, for the party’s failure to muscle through an overhaul of the Affordable Care Act. The president also urged McConnell to “get back to work” on that and other campaign promises, including cutting taxes and spurring new infrasturcture spending.

Speaking to reporters Thursday afternoon, Trump declined to say whether McConnell should resign but said they should ask him again if the Senate leader fails to deliver on the president’s leading priorities.

Trump’s said he was particularly miffed by a Senate vote to repeal the Affordable Care Act that failed by a single vote.

“For a thing like that to happen is a disgrace, and frankly it shouldn’t have happened, that I can tell you,” Trump said.

Trump associates said the attacks, which began Wednesday night and resumed on Thursday, were intended to shore up Trump’s outside-the-Beltway populist credentials and would likely resonate with core supporters frustrated by a lack of progress in Washington.

But the tweets were quickly met with public and private defenses of McConnell — and rebukes of Trump. Sen. Orrin Hatch, R-Utah, tweeted: “@SenateMajLdr has been the best leader we’ve had in my time in the Senate, through very tough challenges. I fully support him.” And former House Speaker Newt Gingrich, a Trump adviser, said on Fox News that the president bears some responsibility for the Republican failure on Obamacare.

“The fact is with a very narrow margin — 52 people — Mitch McConnell got 49 out of 52,” Gingrich said. “I think the president can’t disassociate himself from this. “(Trump) is part of the leadership team. He is not an observer sitting up in the stands. He is on the field. It was a collective failure.”

Even some Republicans close to the president suggested the move would hurt him on Capitol Hill, where relations with GOP leaders are already seriously frayed.

“This strategy only alienates his Republican colleagues on Capitol Hill that he needs to move his agenda,” said one Republican strategist close to the White House who requested anonymity to speak more candidly. “The reality is that the president is now part of this process despite his frustrations, and yelling at his Senate quarterback isn’t going to help achieve these wins.”

Trump, who is on a working vacation at his private golf club in Bedminster, N.J., has remained bitter about the collapse of Republican efforts to repeal and replace former President Barack Obama’s health law, a pledge the party has made since 2010 and a marquee campaign promise for Trump.

“Can you believe that Mitch McConnell, who has screamed Repeal & Replace for 7 years, couldn’t get it done,” Trump wrote on Twitter on Thursday morning. “Must Repeal & Replace ObamaCare!”

A few hours later, the president took to Twitter again, writing: “Mitch, get back to work and put Repeal & Replace, Tax Reform & Cuts and a great Infrastructure Bill on my desk for signing. You can do it!”

Trump’s tweets came in the wake of McConnell’s suggestion earlier in the week that Trump’s lack of political experience had led to “excessive expectations” for passing major legislation.

The president has also faced heavy criticism for the fate of the health-care legislation. While he repeatedly called on lawmakers to dismantle Obamacare, he did relatively little to help develop — or sell — their replacement plans to the public at a time when polls showed the legislation was highly unpopular.

Trump’s tweets this week come as lawmakers are poised to try to tackle other shared but challenging priorities when they return from their August recess. Besides Trump’s leading agenda items, they are also faced with trying to craft a budget and raise the nation’s debt ceiling.

“Discerning a particular strategy or goal from these tweets is hard,” said Doug Heye, a Republican National Committee communications director and former Capitol Hill staffer.