Attorney General William P. Barr accused Democrats on Friday of using their oversight powers to sabotage the executive branch, criticizing the “resistance” to President Trump and what he called a broader erosion in the commander in chief’s rightful authority.

The Trump appointee described a “war” against a “duly elected government” at a conference of the Federalist Society, a conservative legal group that has played a key role in the administration’s efforts to seat record numbers of right-leaning federal judges.

“The fact of the matter is that, in waging a scorched earth, no-holds-barred war of resistance against this administration, it is the left that is engaged in the systematic shredding of norms and the undermining of the rule of law,” Barr told his audience of lawyers at Washington’s Mayflower Hotel.

To critics, the speech was overly partisan and even “authoritarian.” It prompted some calls for Barr’s impeachment from lawyers and legal scholars, many of whom believe his views of presidential power are too expansive. Barr says the Constitution’s creators envisioned a strong executive.

His speech came amid a newly public, high-stakes phase of Democrat-led investigations into the White House, as impeachment hearings examine whether Trump abused his office to secure a foreign country’s probe of his political rival. Barr recently declined Trump’s request that he hold a news conference defending Trump in the inquiry by saying the president broke no laws in a call to Ukraine’s president, individuals familiar with the situation told The Washington Post.

But the attorney general was vociferous Friday in his defense of Trump’s actions in office, saying legislators are the ones who have overstepped their bounds. Judges, too, have interfered with the president’s authority in recent years, he said.

“I don’t deny that Congress has some implied authority,” he said. “But the sheer volume of what we see today, the pursuit of scores of parallel investigations through an avalanche of subpoenas, is plainly designed to incapacitate the executive branch and indeed is touted as such.”

Richard Painter, who served as chief White House ethics attorney in the George W. Bush administration, called the attorney general’s statements “authoritarian,” comparing the Federalist Society talk to another Barr speech that criticized “radical secularists.”

Barr’s talk was “an attack on our Constitution and on the rule of law,” the University of Minnesota law professor tweeted.

The speech drew praise, however, from Trump supporters who have long said the administration has been unfairly attacked. Inside the Mayflower Hotel, Barr got enthusiastic applause.

The attorney general has been warning for decades of “legislative encroachments” on the president’s power, as he put it in a 1989 memo that his Democratic successor quickly replaced with one that recognized a bigger role for Congress.

Speaking Friday, Barr traced a “steady grinding down” of executive authority to the mid-1960s, saying the trend had quickened after the Watergate scandal that led to President Richard Nixon’s resignation.

Barr emphasized the president’s purview over policy and diplomacy and argued for the executive branch’s ability to keep its conversations secret from what he called a meddling Congress. For the attorney general, the so-called resistance to the president implies a “dangerous” notion of insurgency against a military occupation.

He pointed to Trump’s election as a mandate for his actions.

“While the president has certainly thrown out the traditional Beltway playbook and punctilio, he was up front about what he wanted to do, and the people decided they wanted him to serve as president,” Barr said.

The attorney general defended specific Trump administration policies such as a travel ban aimed at citizens of mostly majority-Muslim countries, pointing to court victories. The Supreme Court upheld that policy last year in a close ruling that found Trump can bar travelers for national security reasons.

Barr contended the Obama administration wielded executive power more aggressively than its successor — for example, through its creation of the Deferred Action for Childhood Arrivals program that protects certain undocumented immigrants known as “Dreamers” from deportation.

Barr’s speech reiterated views that were controversial during his confirmation earlier this year, too.

His “vision of presidential power is contrary to the constitutional system of checks and balances that lies at the heart of our Constitution,” Neil Kinkopf, a law professor at Georgia State University, testified at hearings on Barr’s nomination.

Democrats were especially wary of how Barr would handle special counsel Robert S. Mueller III’s investigation of the president, pointing to a 2018 memo Barr wrote arguing that Mueller was interpreting obstruction of justice too liberally. In hearings, Barr would not promise to release the special counsel’s report.

Barr was confirmed in a 54-45 vote falling mostly along party lines.