President Donald Trump's public attacks on two GOP senators could further reduce his clout with congressional Republicans just as he enters a series of key policy discussions.

In Wednesday morning tweets, Trump slammed Sens. Lindsey Graham, R-S.C., and Jeff Flake, R-Ariz. Those messages follow his recent public chiding of Senate Majority Leader Mitch McConnell and a string of statements in which GOP lawmakers distanced themselves from the president after his response to a white nationalist rally in Virginia over the weekend.

The tensions could leave Trump's White House with limited sway over the upcoming policy discussions or lead to lawmakers outright disregarding the president's suggestions, congressional watchers said.

"He's lost the Congress at this point. I can't imagine he's going to be able to repair the damage that's done," said Steven Billet, director of the legislative affairs program at the George Washington University Graduate School of Political Management.

The president's relationships with Republican senators, in particular, appear increasingly strained as Congress looks to approve a debt ceiling increase and pass an appropriations bill after lawmakers get back from recess next month. The GOP also aims to approve a tax-reform bill by the end of the year; Trump wants a massive infrastructure package after that.

For issues like tax reform, beleaguered lawmakers could simply choose to work through legislation without the White House, said Greg Valliere, chief global strategist at Horizon Investments who tracks Washington for investors.

"I think Republicans in Congress increasingly are unified in their goal to just go it alone and virtually ignore the White House," he said. "This may embolden Republicans to move on their own. I think if we get legislative accomplishments, it will be in spite of Trump, not because of Trump."

The president lambasted the Republican senators in early morning tweets. He first slammed "publicity seeking" Graham, after the senator criticized the president's fiery Tuesday comments about an attack at the white nationalist rally that killed one person and left many others injured. Trump appeared to suggest equivalence between the white nationalists and demonstrators protesting against them.

Graham responded pointedly Thursday, telling Trump that "because of the manner in which you have handled the Charlottesville tragedy you are now receiving praise from some of the most racist and hate-filled individuals and groups in our country."

"For the sake of our nation — as our president — please fix this," Graham said in a statement. "History is watching us all."

Shortly after hitting Graham, Trump then publicly highlighted Kelli Ward, the candidate running against Flake for his seat next year. Trump called Flake "toxic," "WEAK on borders" and crime, and a "non-factor in the Senate."

Flake recently wrote a pointed book criticizing what Trump has done to the Republican Party. At least two notable GOP senators — John McCain of Arizona and Bob Corker of Tennessee — came out in support of Flake after Trump's tweet.

In response, a Flake campaign spokesman said: "You don't serve Arizona by cutting backroom deals in Washington, D.C. That's why Sen. Flake will always fight for the people of our state."

In criticizing Graham, Flake and McConnell, Trump has also gone after senators who have largely supported his agenda.

Both Graham and Flake have fallen pretty reliably on Trump's side on most issues, voting with the president's position about 92 percent and 94 percent of the time, respectively, according to FiveThirtyEight.

McConnell — who Trump has repeatedly chided for failing to pass an Obamacare repeal bill — has voted with the president's position about 96 percent of the time.

Republican senators had already started to disregard Trump's suggestions on how to do their jobs. After Senate GOP efforts to repeal and replace Obamacare flamed out late last month, Trump repeatedly called on senators to keep trying.

They largely shifted focus to tax reform, while the GOP head of the Senate committee overseeing health care is holding hearings next month on ways to stabilize Obamacare markets.

The White House did not immediately respond to a request for comment.