Over the last 100 days, one thing has become indisputably clear: More than any other member of President Donald Trump’s Cabinet, Attorney General Jeff Sessions is the keeper of the flame.

He unflinchingly advances the president’s ideological priorities and frequently appears in conservative media to tout that work. He may be better at keeping Trump’s campaign promises than the president is himself. Like Eric Holder before him, he’s the ideological lodestar to the president—a true believer’s true believer.

In the last 100 days, everyone else has disappointed. House Speaker Paul Ryan couldn’t get his House conference to repeal Obamacare. Secretary of State Rex Tillerson and United Nations Ambassador Nikki Haley exchanged friendly fire on the Sunday shows over what exactly the administration wanted to do in Syria. Gary Cohn, Jared Kushner, Steve Mnuchin, and the rest of the Goldman gang have undercut Trump’s populist bona fides and reportedly muscled out the White House’s most ideological senior staff. Mike Flynn got axed, K.T. McFarland got shipped to Singapore, and Betsy DeVos—well, she’s trying.

But as bedlam has unfolded at 1600 Pennsylvania Ave., six blocks east in a quiet office on the fifth floor of the imposing Robert F. Kennedy Department of Justice Building, Sessions has busily kept Trump’s campaign promises for him. The attorney general is prioritizing immigration prosecutions, delighting police unions, perusing the border to warn would-be undocumented immigrants to stay away, and rolling back the Justice Department’s litigation against voter-ID laws.

He generated extraordinary opposition from the moment his nomination was announced, with Democrats and civil-rights activists ripping into his stances on immigration, policing, and voting rights. A back-bench Democratic congressman recently called him “a racist and a liar,” and one of his Senate colleagues, Cory Booker, took the unprecedented step of testifying against him at his confirmation hearing. None of that has slowed Sessions.

“I think he’s one of the most successful individuals in Washington right now,” said John Ashcroft, George W. Bush’s first attorney general. “It’s an agenda which he helped shape in the campaign and it’s an agenda with which he’s very comfortable.”

Sessions has demonstrated a high comfort level with making sweeping changes, and fast. He reversed the previous administration’s decision to stop contracting with private prisons, he directed every U.S. Attorney’s office to make someone responsible for overseeing prosecutions of immigration offenses, and directed those offices to focus on going after people who illegally re-enter the U.S. after being deported. He sent more than two dozen immigration judges to the border to speed up deportations, and he moved quickly to hire dozens more. He’s also threatened to cut federal grant funding to cities like New York and Chicago that block their law-enforcement officers from fully cooperating with the feds on immigration enforcement, sending a shiver of fear through city mayors and managers.

Sessions’s most ardent opponents and devoted supporters agree on one thing: He’s incredibly predictable. Through his decades in public life, he’s never flinched in his opposition to illegal immigration, his skepticism about the Justice Department’s use of court orders to push for police reform, and his support for tough-on-crime drug enforcement.

“He’s been a very consistent voice in opposition to any number of civil-rights issues,” said Sherrilyn Ifill, the president of the NAACP Legal Defense Fund. “No one can say that they didn’t know who he was.”

“There’s a heightened consciousness about what he represents, about this administration and where it stands on civil rights, and as a result we have calls like never before, support like we haven’t seen in a very long time,” she added. “We are inundated with offers of people saying, ‘How can I help?’”

On policing in particular, Sessions is poised to undercut much of President Obama’s legacy. During Obama’s presidency, the Civil Rights Division of the Justice Department investigated a host of police departments for civil-rights violations and then negotiated court-enforced agreements—called consent decrees—with them. Civil-rights advocates cheered that effort as the only way the federal government could effectively pressure troubled departments to embrace reform.

But many conservatives and police unions said the agreements were meddlesome federal overreach and only served to discourage police officers. Sessions shares those concerns and has ordered staff to review all current and pending consent decrees with an eye to making changes that could boost officer morale. Civil-rights advocates have ripped Sessions’s decision.

“He is picking and choosing which laws he intends to enforce,” said Ifill. “The impact is that those of us who do this work are stepping up and having to expend our resources to fill in and stand strong where the DOJ has failed to enforce civil-rights laws.”

Ashcroft, however, praised Sessions’s move.

“I think one of the big challenges for the country right now is what has been the prior administration’s disrespect for the rule of law and, as a result, disrespect for law-enforcement officials,” he said. “And the idea that we’ve had law-enforcement officials whose lives have been taken in ambush attacks—and nearly a couple dozen of them in the last year—is a terrible outcome when you consider what the rule of law means, not only for their personal safety but to the idea of liberty in America.”

Sessions has criticized the federal judge who blocked Trump’s travel ban, iterated and reiterated and re-reiterated that all undocumented immigrants—DREAMer or not—are subject to deportation, and become one of the Trump Cabinet’s most visible faces in conservative media. He’s appeared several times on Fox News (twice with Tucker Carlson, the new center of its prime-time lineup) and called in to a bevy of conservative talk radio shows—Hugh Hewitt, Laura Ingraham, Mark Levin, Lars Larson, Howie Carr, you name it.

Whether it’s on purpose or not, Sessions is becoming the White House’s de facto emissary to its base. And the base is happy. Mark Krikorian, who heads the immigration restrictionist think tank Center for Immigration Studies, told The Daily Beast he’s delighted with Sessions’s time at Justice thus far.

“Sessions is Trump’s Good Housekeeping Seal of Approval,” he said. “If Sessions ever gets to the point where he says, ‘Look, I can’t work for this administration anymore,’ then it’s all over for Trump.”

“I’m certain that Sessions will do the right thing,” Krikorian added. “I don’t have to hope about that.”

Sessions could face some of the thorniest challenges confronting an attorney general in recent memory—namely, policing the Trump White House, where some aides appear to treat ethics rules with reckless abandon.

“I’m a partisan,” said Matt Miller, a spokesman for Eric Holder during his time as attorney general. “But this is not a partisan statement: The people in this White House are going to do a lot more legally questionable things than happened in other White Houses. They’re just sloppy and inexperienced, and in some ways, I think, morally compromised. Your Seb Gorkas of the world are not your typical White House employees.”

Sessions has already recused himself from anything related to investigations of connections between members of the Russian government and Trump campaign officials during the election—a recusal that came after The Washington Post reported that he didn’t disclose to the Senate Judiciary Committee that he himself had met with the Russian ambassador.

That didn’t appear to slow Sessions down. Instead, he’s moved with inexorable efficiency to advance Trump’s agenda. While Congress dithers and Cabinet secretaries argue among themselves, the attorney general has used his extraordinary power as the nation’s chief law enforcement officer to start dismantling Obama’s signature endeavors—impervious, thus far, to extraordinary levels of outside criticism.

“The dogs may bark,” Ashcroft said, “but the caravan moves on.”