From the Russia investigation to health care, President Trump has not shied away from fighting those in his own party – especially on social media.

Here’s a look at some of the Republican lawmakers Trump has feuded with since he’s taken office.

Bob Corker

Tennessee Sen. Bob Corker announced in 2017 that he would retire at the end of his term – and Trump credited himself with the decision.

“Senator Bob Corker ‘begged’ me to endorse him for re-election in Tennessee. I said ‘NO’ and he dropped out (said he could not win without my endorsement),” Trump said on Twitter, adding that he also denied Corker a position as secretary of state.

Trump blamed Corker, who he nicknamed “Liddle Bob Corker” for the Iran nuclear deal and said he couldn’t “get elected dog catcher in Tennessee.”

But Corker wasn’t without his own jabs at the administration. He said the “White House has become an adult day care center” and accused Trump of having “not demonstrated he understands the character of this nation” following the Charlottesville attack. He also credited White House chief of staff John Kelly, Defense Secretary James Mattis and Secretary of State Rex Tillerson with “help[ing] to separate our country from chaos.”

Jeff Flake

When Arizona Sen. Jeff Flake announced he would not seek re-election, he took the opportunity to call the president “reckless, outrageous and undignified” from the Senate floor.

Prior to Flake’s speech, Trump called the lawmaker “weak,” particularly on the issue of illegal immigration. He also encouraged Kelli Ward, a controversial Republican, to run against Flake.

Flake, who didn’t vote for Trump in the presidential election, again escalated the fracas between the two men when he publicly shared a check he wrote to then-Democratic Senate candidate Doug Jones with the subject line saying, “Country over Party.” Jones beat Roy Moore, the beleaguered Republican accused of sexual misconduct in the special election in December 2017.

Additionally, Trump has nicknamed the senator “Flake(y).” And Flake accused Trump of having “inspired dictators and authoritarians with his own rhetoric.”

Lindsey Graham

Ever since Trump gave out former GOP candidate Lindsey Graham’s cell phone number during the presidential campaign, the two’s on-again-off-again relationship has continued.

Graham, a senator from South Carolina, clashed with Trump following his response to the attack in Charlottesville in 2017.

“President Trump took a step backward by again suggesting there is moral equivalency between the white supremacist neo-Nazis and KKK members who attended the Charlottesville rally and people like Ms. Heyer,” Graham said, referencing the woman who died when a man drove his car into a crowd of people protesting white supremacists. “I, along with many others, do not endorse this moral equivalency.”

Trump, in turn, accused Graham of “publicity seeking.”

While the pair seemingly came together during efforts to repeal ObamaCare, Graham and Trump again clashed over immigration.

After Graham partnered with Sen. Dick Durbin, D-Ill., on an immigration bill, the White House accused them of being “completely dishonest” in negotiations.

Graham admonished the administration, saying, “If you continue this attack on everything and everybody and make it a political exercise, we’re doomed to fail, and it is President Trump’s presidency that will be the biggest loser.”

John McCain

The fight between Arizona Sen. John McCain and Trump started during the campaign – and escalated when the then-presidential candidate said McCain was a “war hero because he was captured.”

“I like people who weren’t captured,” Trump said at a 2015 Iowa event.

Since that comment, the two have feuded over a variety of issues, especially when it came to health care reform.

McCain, who is suffering from an aggressive form of brain cancer, voted against a so-called “skinny repeal” of ObamaCare in July 2017. And Trump seemingly hasn’t forgotten it.

In a radio interview in 2017, Trump called McCain’s vote a “tremendous slap in the face to the Republican Party.” And during a speech to those gathered at the Conservative Political Action Conference (CPAC) in February 2018, Trump criticized McCain’s vote, shaking his head.

Daughter Meghan, a host on “The View,” said she recently spoke to the president and first lady Melania Trump. During the conversation, she said she “was under the impression that this sort of fight between our families, and between him and my father especially at this particular moment, would end.”

Mitch McConnell

Trump and Senate Majority Leader Mitch McConnell haven’t had the steadiest of relationships since Trump won the White House. The pair have fought over a variety of issues, including health care, the debt ceiling and the investigation into Russia’s involvement in the 2016 election.

McConnell has also reportedly questioned Trump’s governing style in both public and private comments.

Trump, in turn, blamed McConnell for having “failed” to repeal and replace the Affordable Care Act.

Jeff Sessions

Attorney Gen. Jeff Sessions has often found himself the target of Trump’s wrath – especially online.

More recently, Trump blasted Sessions for instructing an “Obama guy” to investigation allegations of government surveillance abuse that came to light after memos were released about FBI and DOJ efforts to obtain FISA warrants to spy on a former Trump campaign adviser.

“Why is A.G. Jeff Sessions asking the Inspector General to investigate potentially massive FISA abuse. Will take forever, has no prosecutorial power and already late with reports on Comey etc. Isn’t the I.G. an Obama guy? Why not use Justice Department lawyers? DISGRACEFUL!” Trump said on social media.

In a statement, Sessions said, “As long as I am the Attorney General, I will continue to discharge my duties with integrity and honor, and this Department will continue to do its work in a fair and impartial manner according to the law and Constitution.”

Sessions also drew much consternation from the president when he recused himself from the Russia investigation.

Trump later lashed out at Sessions online.

“If all of the Russian meddling took place during the Obama Administration … why aren’t they the subject of the investigation?” Trump tweeted.