A Democrat-run group on Tuesday pushed a hashtag calling on Sen. Lindsey Graham (R-SC) to resign, after the South Carolina senator said Donald Trump Jr. should ignore a subpoena issued to him by Sen. Richard Burr (R-NC) to testify again before Congress.

One Democrat operative, Jon Cooper, acknowledged that the hashtag “LindseyGrahamResign” was promoted by the Democratic Coalition, an anti-Trump organization formed in Spring 2016.

“The organization now exists to hold the Trump White House accountable, and is directly countering Donald Trump, along with Republican elected officials and candidates who support him, through aggressive digital and traditional advertising, grassroots action, in-depth opposition research, and a nationwide rapid-response team,” its website’s “About Us” section said.

Chairman of the Democratic Coalition, Jon Cooper, bragged about his group’s work on Tuesday morning in a tweet:

BREAKING: #LindseyGrahamResign has been tweeted out over 20,000 times since @TheDemCoalition started to promote it this morning. Graham SHOULD resign. Him telling Don Jr to ignore a Senate subpoena is more than enough to warrant his resignation. Everyone who retweets this agrees. — Jon Cooper (@joncoopertweets) May 14, 2019

The hashtag has been trending nationally all Tuesday morning and afternoon, according to Twitter’s tracker.

Democrat operatives are demanding Graham resign over his advice to Trump Jr. to ignore a subpoena issued as part of the Senate Intelligence Committee’s investigation into Russian interference in the 2016 election and any alleged collusion.

Although Special Counsel Robert Mueller’s investigation found no evidence of any kind of criminal collusion, conspiracy, or coordination between the Trump campaign and Russia, the Senate committee has not yet wrapped up its probe.

Burr said in February there is no evidence of collusion, but he reportedly is calling Trump Jr. back in to settle discrepancies between his and former Trump lawyer Michael Cohen’s testimony earlier this year.

Republicans have slammed Burr’s subpoena and have called on him to rescind it, but he has shown no signs of doing so.

The Democrat uproar over Graham began when he commented on Fox News on Sunday, “If I were Donald Trump Jr.’s lawyer, I would tell him you don’t need to go back into this environment anymore.”

“You’ve been there for hours and hours, and nothing being alleged here changes the outcome of the Mueller investigation. I would call it a day,” he said. He later told reporters that he was suggesting Trump Jr. appear, but to plead the Fifth.

Graham has emerged as a staunch Trump supporter, and has pledged to investigate the origins of the FBI’s probe into the Trump campaign in 2016.