WASHINGTON — When President Trump nominated William P. Barr as attorney general a year ago, establishment Republicans who had chafed at Mr. Trump’s takeover of their party were relieved. Between Mr. Barr’s work in the Reagan White House and his fast-track career under George Bush, he could be a bridge to the Republican Party they knew — and preferred.
How wrong they were.
Mr. Barr has eagerly embraced the most divisive and disputed aspects of the Trump agenda, much to the delight of the party’s hard-line conservatives who see him as an indispensable ally in their fight to push the country further to the right on issues like religious liberty, immigration and policing.
Other conservative attorneys general shared Mr. Barr’s relish for political battle. But as he attacks the Democratic Party, assails liberal culture and defends the president against accusations of abusing his office, Mr. Barr has wielded a maximalist view of executive power and adopted a blithely antagonistic, no-apologies style that set him apart from his predecessors.
That makes him a natural fit in a Republican Party that Mr. Trump has remade in his mold. But it worries critics in both parties who fear that Mr. Barr is eroding the Justice Department’s traditional independence in law enforcement. They point to his handling of the Mueller report, which he summarized in a letter widely seen as more favorable to Mr. Trump, and his appointment of a prosecutor to re-examine the opening of the Russia investigation, which Mr. Trump has long impugned.
To the conservatives who make up the most solid foundation of the president’s base — a wing of the Republican Party that is generally more uncompromising on social issues and enthusiastic about political combat with the left — Mr. Barr is the template of the public servant they envisioned when Mr. Trump promised to give them greater influence in his administration.
He is a devoted Catholic who has said he believes the nation needs a “moral renaissance” to restore Judeo-Christian values in American life. He has been unafraid to use his platform as the nation’s top law enforcement officer to fight the cultural changes they believe are making the country more inhospitable and unrecognizable, like rising immigration and secularism or new legal protections for L.G.B.T. people.
“Attorney General Barr represents an important conservative point of view that is really the heart of the Trump presidency,” said Frank Cannon, the president of the American Principles Project, a social conservative organization.
A series of assertive public appearances in recent weeks, laced with biting sarcasm aimed at adversaries on the left, have brought a sharper focus on Mr. Barr’s style and worldview, both of which share aspects with the president’s.
He has painted a picture of a country divided into camps of “secularists” — those who, he said recently, “seem to take a delight in compelling people to violate their conscience” — and people of faith. The depiction echoes Mr. Trump’s worldview, with the “us versus them” divisions that the president often stokes when he tells crowds at his rallies that Democrats “don’t like you.”
His politicization of the office is unorthodox and a departure from previous attorneys general in a way that feels uncomfortably close to authoritarianism, critics said.
“Barr has believed for a long time that the country would benefit from more authoritarianism. It would inject a stronger moral note into government,” said Stuart M. Gerson, who worked in the Bush Justice Department under Mr. Barr and is a member of Checks & Balances, a legal group that is among the attorney general’s leading conservative detractors. “I disagree with his analysis of power. We would be less free in the end.”
Mr. Barr swats away those critics. “Generally, no one really cares what they think,” he said of Checks & Balances in a recent interview with New York magazine. An accompanying picture showed him grinning ear to ear with his feet propped up on his desk.
That defiance is one reason he has attained an almost heroic status among some on the right, particularly the religious conservatives.
“He’s offering a fairly unabashed, crisp and candid assessment of the nature of our culture right now,” said Leonard A. Leo, the executive vice president of the Federalist Society and a prominent advocate for socially conservative causes. “There’s certainly a movement in our country to dial back the role that religion plays in civil society and public life. It’s been going on for some time,” Mr. Leo added. “That’s not an observation that public officials make very often, so it is refreshing.”
Mr. Barr helped make the case for conservatives to shift to war footing against the left during a speech at Notre Dame Law School in October that was strikingly partisan. He accused “the forces of secularism” of orchestrating the “organized destruction” of religion. He mocked progressives, asking sardonically, “But where is the progress?”
And while other members of the Catholic Church and Pope Francis have acknowledged that the sexual abuse crisis has devastated the moral authority of the church in the United States and is in part to blame for decreasing attendance, Mr. Barr outlined what he saw as a larger plot by the left and others. He said they “have marshaled all the force of mass communications, popular culture, the entertainment industry and academia in an unremitting assault on religion and traditional values.”
At one point, he compared the denial of religious liberty protections for people of faith to Roman emperors who forced their Christian subjects to engage in pagan sacrifices. “We cannot sit back and just hope the pendulum is going to swing back toward sanity,” Mr. Barr warned.
Delivered on a Friday before a holiday weekend to a small, invitation-only crowd, the speech initially drew little attention in mainstream circles. But among politically active Christians, Mr. Barr’s remarks lit a brush fire.
At a dinner with anti-abortion activists shortly after the speech, Secretary of State Mike Pompeo told guests how striking and clarifying he found Mr. Barr’s comments, according to two people who spoke with him.
It was “one of the best speeches any attorney general has ever given,” said Edwin Meese III, the attorney general under Ronald Reagan, who said that he not only liked Mr. Barr’s style but also agreed with his diagnosis of the problems facing the country. Today’s culture, Mr. Meese said, is more hostile than it was for conservative values when he was attorney general in the 1980s. And Mr. Barr is giving voice to those on the right who believe they cannot cede any more ground in the culture wars.
“If you look back in history, there have been various points of renewal,” Mr. Meese added. “And I think his concern, which I would share, is we’re facing a time when the pendulum is not going to swing back.”
Mr. Barr, who personally covers tuition for underprivileged New York City students who wish to attend Catholic school, has prioritized Justice Department cases involving religious institutions. In October, the department filed a brief in support of parents suing over a Maine law that bans religious schools from the state’s school tuition program. It has also argued recently that the Maryland State Education Department discriminated against a Christian academy that said same-sex marriage was wrong.
For the better part of three decades, Mr. Barr has been known in conservative legal circles as a sharp, tight-lipped lawyer who embodied the Reagan and Bush eras. “A fair number of people who were more or less conservative said publicly that it was good that he was coming in because he was a real lawyer who would bring respectability to this administration,” said Donald Ayer, who served in the Justice Department under Reagan and Mr. Bush.
But his longstanding relationships with Trump allies like Pat A. Cipollone, the White House counsel who is a founder of the National Prayer Breakfast and takes part in the anti-abortion March for Life, and Laura Ingraham, the Fox News host whom Mr. Cipollone introduced to Catholicism, suggest that he was always at ease in the world of social conservatives who have lined up behind Mr. Trump to take on liberals.
In a speech on executive power delivered at a Federalist Society conference last month, Mr. Barr argued that the left’s opposition to the president was a dangerous attempt to overturn the results of the 2016 election and weaken the power of the presidency.
Delivering such a speech amid impeachment proceedings was unusual. During the Clinton impeachment, Janet Reno, then the attorney general, did not castigate Republicans and defend the president’s behavior as Mr. Barr has with Mr. Trump.
“Barr’s language against the ‘left’ and against ‘progressives’ was not something we’d normally hear in a speech by the attorney general,” said Carrie F. Cordero, a national security expert and a co-founder of Checks & Balances who served as a top legal adviser to the director of national intelligence and in the Justice Department.
“It’s embedded in department culture to set those partisan views aside when doing your work and applying the law,” Ms. Cordero said.
Defenders say Mr. Barr feels emboldened to criticize Democrats because he believes they crossed a line during his confirmation hearings when they accused him of being blindly deferential to Mr. Trump. The same general sentiment is one shared by the president, who also believes he is the victim of unfair attacks from the left.
“Their critics went too far too fast,” said Kellyanne Conway, the White House counselor who first met Mr. Barr years ago through Ms. Ingraham. “And you reap what you sow.”
Mr. Barr and Mr. Trump have both staked out far-right positions on issues like aggressive policing, with the attorney general serving as the polished ego to the president’s unbridled id.
Last week, for instance, Mr. Barr said that communities who criticized policing needed to show more respect or they “may find themselves without the police protection they need.”
Both conservative supporters and critics of Mr. Barr insist that he is not doing the president’s bidding, as many on the left suggest. Rather, they say, he is empowered by Mr. Trump, who has not interfered with an attorney general who provides him the legal justification for his instinct-driven approach to the presidency. That leaves room for Mr. Barr to carry out Mr. Trump’s agenda through the prism of his own sweeping views of executive power.
“Barr has an opportunity to test legal theories that no other president would give Barr the opportunity to test,” Mr. Ayer said.