Attorney General William Barr, who has served as President Donald Trump’s most effective shield and advocate for broad presidential authority, will resign next week as the administration draws to a disputed close.

Trump announced the news of Barr’s departure Monday evening on Twitter. 

Trump lauded his attorney general as “a man of unbelievable credibility and courage” just months ago, but turned on Barr after he declared there was no widespread evidence of voter fraud in the 2020 presidential election and resisted Trump’s public pressure to prosecute President-elect Joe Biden and other former Obama administration officials on baseless claims of corruption and the surveillance of the 2016 race.

Over the weekend, Trump rebuked Barr for not revealing a recently disclosed inquiry into Hunter Biden’s taxes during his failed campaign in which the president sought to tie President-elect Joe Biden to his son’s financial dealings.

On Monday, however, there were no ugly words from Trump who announced Barr’s departure in a tweet, saying the decision came after a “pleasant meeting” at the White House.

In his resignation letter, Barr also thanked Trump and offered a forceful defense of his boss.

Barr praised what he described as Trump’s accomplishments “in the face of relentless, implacable resistance” and singled out the Russia investigation as a partisan attack on Trump’s presidency.

“The nadir of this campaign was the effort to cripple, if not oust, your administration with frenzied and baseless accusations of collusions with Russia,” Barr wrote. “Few could have weathered these attacks, much less forge ahead with a positive program for the country. You built the strongest and most resilient economy in American history — one that has brought unprecedented progress to those previously left out.”

Barr’s is set to leave Dec. 23. Deputy Attorney General Jeff Rosen will be acting attorney general, Trump said as he announced Barr’s resignation.

Trump tweeted the announcement just minutes after California announced it had awarded its electoral votes to Joe Biden, giving him a majority in the Electoral College and formally making him president-elect.

​Trump and Barr met at the White House Monday where they reached “an amicable understanding” of how things should proceed, a senior administration official said. Barr “was not asked to resign,” the official said.

Senate Judiciary Chairman Lindsey Graham, R-S.C., a vocal defender of both Barr and Trump, said he was “surprised” at the timing of the attorney general’s departure.

“I thought he did a credibly good job trying to repair damage to the Department of Justice, trying to be fair, faithful to the law,” Graham said. “Think he’s got a lot to be proud of.”

Despite Trump’s recent expressions of displeasure, Graham said Barr “fought for the president where he could as every attorney general should … But he also didn’t cross the lines that he shouldn’t have crossed.”

Graham expressed confidence in Barr’s successor.

“Rosen’s a good guy,” Graham said.

Before Rosen’s appointment at Justice, he had no experience as a federal prosecutor.

The president had raised the prospect of Barr’s departure openly after the attorney general broke with Trump, affirming no widespread fraud in the election.

“To date, we have not seen fraud on a scale that could have affected a different outcome in the election,” Barr told the Associated Press on Dec. 1, even as Trump continues to pursue legal challenges to an election he has yet to concede.

The comments quickly prompted push back from Trump’s attorneys, Rudy Giuliani and Jenna Ellis, who said Barr’s “opinion” was not based on “knowledge or investigation of the substantial irregularities and evidence of systemic fraud.”

Although Trump and his allies have publicly made sweeping claims of widespread fraud, the campaign did not make such unfounded allegations in courtrooms as it sought to challenge election results. 

Apart from members of Trump’s own family who serve in the administration, Barr appeared to have few rivals in the president’s inner-circle where he repeatedly rose to defend the president and his political allies while drawing withering criticism from Democrats and scores of Justice Department alums who cast the attorney general as the president’s personal lawyer.

Indeed, Barr intervened earlier this year in criminal cases involving two former Trump aides — political adviser Roger Stone and national security adviser Michael Flynn — prompting his own prosecutors to withdraw from the cases in protest. Barr recommended a lighter punishment for Stone whose sentence was ultimately commuted by Trump. He pardoned Flynn, who’d pleaded guilty to lying to the FBI about his contacts with a Russian ambassador.

More:DOJ drops case against former Trump adviser Michael Flynn in boldest step yet to undermine Mueller probe

Whatever goodwill those efforts earned, it was clearly not enough, as Trump dumped his second attorney general like so many other former close aides.

Barr began his second stint as the nation’s chief law enforcement officer, having served in the George H.W. Bush administration, on Valentines Day 2019 following the equally tumultuous term of Jeff Sessions. The former Alabama lawmaker, the first senator to have endorsed Trump in the 2016 campaign, permanently fell from favor after he recused himself from the Russia investigation, prompting the appointment of special counsel Robert Mueller.

The nomination of Barr, whose ties to Justice pre-date Trump’s political fortunes, appeared to buoy a Justice Department under constant siege by the president who had fired FBI director James Comey and lashed out almost daily at Sessions.

Just weeks into his tenure, however, Barr startled some lawmakers when he suggested that federal investigators had spied on Trump’s campaign and announced the appointment of a Connecticut federal prosecutor, John Durham, to review the origins of the Russia investigation. The results of that inquiry, long-anticipated by Trump, have been delayed in part by issues related to the coronavirus pandemic.

But it was Barr’s handling of the Russia investigation – effectively clearing the president of wrongdoing despite damning findings that Trump repeatedly sought to thwart the inquiry – that first raised serious questions about the independence of the Barr Justice Department.

Rep. Jerry Nadler, chairman of the House Judiciary Committee, castigated Barr for his handling of the Mueller report and politicization of the Justice Department.

“In 37 days, President-Elect Joe Biden will be sworn into office. Whomever Joe Biden chooses as the new Attorney General will have a tremendous amount of work to do to repair the integrity of the Department of Justice,” Nadler said in a statement.

Since the Russia probe, Barr has offered vocal defenses of the president, even as Trump faced impeachment proceedings in the House of Representatives.

That attorney general used his platform to accuse the president’s political enemies of “harassment” and “sabotage,” while taking a lead role in supporting Trump’s law-and-order agenda during the 2020 campaign.

Barr also has provided back-up to Trump’s unsupported claims that mail-in balloting was vulnerable to massive fraud that threatened the integrity of the election. And last month, during a speech at a local college, Barr defended his intervention in criminal cases, making the biting claim that his own federal prosecutors “sometimes become headhunters” when pursuing high-profile targets.

Breaks in the Trump-Barr relationship began to show this fall when the president ramped up the pressure on his attorney general, openly calling on him to use the power of his office against Biden and others.

“Unless Bill Barr indicts these people for crimes, the greatest political crime in the history of our country,” Trump told Fox Business News, accusing Biden and former President Barack Obama of election interference, “then we’re going to get little satisfaction unless I win.”

House Intelligence Committee Chairman Adam Schiff, D-Calif., offered a pointed commentary on Barr’s tenure, following Trump’s announcement.

“Lied to cover for Trump,” Schiff tweeted, referring to Barr’s favorable spin on Trump’s role in the Russia investigation. “Launched political investigations. Subverted justice and the rule of law… Now, the work of restoring a credible and independent justice system must begin.”