WASHINGTON — President Trump once again showed this weekend that when it comes to attacking political opponents, he is bipartisan.

His Twitter dustup with fellow Republican Bob Corker in response to the Tennessee senator's criticism of the president's sometimes erratic behavior would appear to further imperil Trump's legislative agenda.

With a narrow Republican margin of 52 to 48 in the Senate, you'd expect Trump would be trying to curry favor within the GOP caucus.

Yet, he has now singled out 11 GOP senators for discouraging words, mostly on Twitter, some while he was running for the presidency and some since he took office. Here is a rundown of those senators and a sampling of the harshest barbs they have endured.

AS PRESIDENT

Bob Corker of Tennessee

Corker has several times questioned Trump's stability and temperament; on Wednesday he said Secretary of State Rex Tillerson, Defense Secretary Jim Mattis and White Hosue Chief of Staff John Kelly "help separate our country from chaos."

Trump fired back Sunday morning:

Corker, who is not seeking re-election, responded in kind:

John McCain of Arizona

Trump has had an ongoing battle with McCain that goes back several years.

Trump unloaded on McCain during an event in Ames, Iowa.

"He’s not a war hero. He is a war hero because he was captured,” Trump said. “I like people that weren’t captured, OK? I hate to tell you.”

After McCain voted "no" on a bill to repeal the Affordable Care Act, Trump was back on the warpath.

Lindsey Graham of South Carolina

Graham, a presidential rival, has taken fire from Trump both as a candidate and a senator. When Graham questioned Trump's comments after racially motivated protests in Charlottesville, Virginia, the president responded.

But apparently Graham does not hold a grudge — he rode with the president to Trump's suburban D.C. golf course for a Columbus Day outing Monday, and praised Trump's golf game afterward.

Lisa Murkowski of Alaska

Murkowski drew Trump's ire when she voted against legislation that would have partly repealed and replaced the Affordable Care Act, known as Obamacare.

Jeff Flake of Arizona

Flake and Trump have feuded for some time with Trump endorsing his rival in the GOP primary. Flake is considered one of the most endangered Republican senators up for re-election next year.

Dean Heller of Nevada

Speaking at a White House lunch in July with Heller present, Trump questioned whether he wanted to be in the Senate anymore.

"This was the one we were worried about," Trump said, motioning to Heller, who was seated next to him. "You weren't there, but you're going to be."

Heller had earlier said he would vote against a health care reform package favored by Trump.

After a pause for laughter, Trump continued: "Look, he wants to remain a senator doesn't he?"

Many took Trump's comments as a threat.

Mitch McConnell of Kentucky

Trump has placed much of the blame for Congress failing to repeal and replace the Affordable Care Act at the feet of Senate Majority Leader Mitch McConnell. He has incessantly badgered McConnell for failing to pass a bill, and has suggested changing Senate rules to eliminate the filibuster, which McConnell has said he will not do.

AS A CANDIDATE

Of course, during the campaign season, Trump was not shy about tweeting criticism of his opponents who happened to be U.S. senators:

Ted Cruz of Texas

Rand Paul of Kentucky

Marco Rubio of Florida

Ben Sasse of Nebraska

Sasse was a vocal Trump opponent during the 2016 campaign, season, saying he could never vote for Trump