Jeff Sessions is out. At the request of the president, the attorney general submitted his resignation letter to the White House the day after this week’s midterm elections.

His ouster was long expected. Ever since Sessions recused himself in March 2017 from overseeing the Justice Department investigation into alleged Russian interference in the 2016 election, Trump had been at his throat, criticizing his job performance on Twitter and reportedly berating him in the Oval Office. The New York Times described Trump and Sessions’s relationship as “one of the most acrimonious public standoffs between a commander in chief and a senior cabinet member in modern American history.”

Yet in spite of Trump’s obvious contempt for Sessions, the attorney general was one of the president’s most effective champions. Both men have based their vision for the country on white supremacy, and from his perch at Justice, Sessions did everything in his power to complement Trump’s brutality.

The starkest manifestation of their joint vision revealed itself in the administration’s treatment of immigrants in general, and Central American asylum seekers in particular; the family-separation initiative, a horrific, ongoing display of state-sponsored trauma, will be a stain on America’s reputation for generations. But while Trump boisterously proposed outlandish, even illegal immigration policies, Sessions took a quieter approach, exploiting his authority through legal minutiae. In the process, he inflicted long-lasting damage on the asylum system.

The (A-B-)Cs of Sessions’s Asylum Game

It has long been the case that the attorney general has overwhelming authority over the interpretation and enforcement of immigration law in the United States. Jeff Sessions had final say over who was targeted for immigration-related criminal proceedings—hence his infamous “zero tolerance” policy mandating the prosecution of all unauthorized migrants caught crossing the border, the cornerstone of family separation. His successor will be equally empowered.

As head of the Justice Department, which houses the country’s immigration court system, Sessions also had the power to, at will, snatch cases from the immigration appeals courts and unilaterally impose his own rulings on them, setting crucial precedents for other cases. It is through this authority that Sessions surreptitiously dismantled the asylum system. Like an ultraconservative Supreme Court of one, he cherry-picked a handful of pending asylum cases that he could use to issue disastrous legal guidance.

From his confirmation in February 2017 to his resignation Wednesday, Sessions exercised his judicial power several times—overturning, among other things, immigration judges’ power to close cases and dismiss deportation proceedings, which strained the courts and put in jeopardy the ability of hundreds of thousands of immigrants to live in the United States. His docket took a particularly destructive turn last March, when he referred to himself a case, dubbed Matter of A-B-, involving a woman who sought asylum after enduring more than a decade of beatings, death threats, rape, and stalking by her ex-husband in El Salvador.

When Sessions commandeered A-B- from the Board of Immigration Appeals—the appellate level of the immigration-court system—he issued a one-page statement addressing the question of whether “a victim of private criminal activity” (such as spousal abuse) can be considered part of a “particular social group” for purposes of granting asylum. Past court decisions on the question were clear: Retired immigration judges, the American Immigration Lawyers Association, several civil society organizations, and even lawyers within Trump’s Department of Homeland Security filed briefs informing Sessions that, indeed, decades of case law have affirmed domestic violence victims’ eligibility for asylum.

But Sessions wasn’t interested in settled case law. In June, he issued a final decision in Matter of A-B-: “Generally,” he wrote, “claims by aliens pertaining to domestic violence or gang violence…will not qualify for asylum.”

The ruling was more disastrous than many had anticipated. Overnight, Sessions delegitimized the two most common reasons Central American migrants seek legal asylum, thus prompting the nation’s approximately 350 immigration judges—as well as the hundreds of asylum officers who screen asylum seekers for “credible fear”—to err on the side of ordering some of the world’s most vulnerable refugees back to the dangers from which they fled.

Although the most reliable data are still too old to quantify the effects of A-B-, anecdotal evidence from lawyers suggests that it is now a go-to point for prosecutors arguing for asylum seekers’ deportation, and it has prompted both asylum officers and immigration judges to deny a significantly greater proportion of Central Americans’ cases.

Sessions’s Unfinished Business, Part 1

In the months between ruling on A-B- and his resignation, Sessions took up a handful of new asylum-related cases, the outcomes of which will be up to his successor to decide. Though these more recent cases may not match A-B- in their power to invalidate large numbers of asylum claims, they still pose powerful threats to the rights of refugees, and further illustrate Sessions’s willingness to wield his authority to terrorize asylum seekers.

One of the Trump administration’s tactics for ridding the country of asylum seekers has been to detain them for as long as possible while they wait for the immigration courts to process their claims. Sessions was all-in on this tactic: He saw extended time in the United States’ miserable detention facilities as fair punishment for “illegal” immigration and a deterrent against future asylum seekers.

In another alphabet-soup case, Matter of M-G-G- (later Matter of M-S-), Sessions saw a way to codify that deterrent in legal precedent.

In February, the Supreme Court issued a ruling declaring that immigrants in custody have no guaranteed right to periodic hearings to determine whether they might be eligible for release. In issuing this decision, the Supreme Court struck down a ruling by the US Court of Appeals for the Ninth Circuit; the justices also handed the case back to the Ninth Circuit to consider what the Constitution has to say on the matter.

Here, Sessions saw an opening, and took up M-G-G- to probe whether the Supreme Court’s findings overrule an old immigration-court decision affirming certain asylum seekers’ eligibility for bond hearings. In doing so, Sessions slithered into the gap between the Supreme Court’s initial draconian ruling, and the question’s uncertain future in the Ninth Circuit. At worst, this could result in years-long detention times for more and more asylum seekers.

Sessions’s Unfinished Business, Part 2

Sessions took up his final immigration case, Matter of Negusie, on October 18, even though it had already been settled after almost 14 years of litigation.

At stake is a nearly hard-and-fast principle of US asylum law dictating that those seeking refuge from persecution may not, themselves, have taken part in the persecution of others. One of the only ways around that principle is to argue that one was threatened or coerced into the persecution—the “duress” defense—and in Negusie, the courts were trying to define exactly what qualifies for such an exception.

In June, the immigration-appeals court issued what was supposed to be its final ruling in Negusie, and with it introduced a five-step test for establishing a successful duress defense. It’s a stringent test—so stringent that Negusie himself, a refugee from forced military service in Eritrea, didn’t pass. But it was still too lenient for Jeff Sessions, who sought to adjudicate what counts as “duress” yet again.

Eliminating the duress defense could have serious repercussions. Asylum seekers, especially women, are often forced to explain why they stashed weapons for criminals, or cooked and cleaned for gangs when seeking bond or pleading their case. The answer is often obvious—they were threatened—but the legal realities are more complex. Establishing precedent to invalidate duress defenses for any of various legal bars to asylum could punish victims and, like Matter of A-B-, delegitimize countless claims—just another of Sessions’s efforts to chip away at the asylum system.

Undoing the Damage

Whether or not Jeff Sessions’s Trump-era successors advance his treacherous immigration and asylum legacy, it’s safe to assume they won’t roll it back. Interim Attorney General Matt Whittaker holds extremist views on executive-over-judicial power, so he’s unlikely to oppose or alter Sessions’s case-law tactic. And given Trump’s fixation on the “migrant caravan” and the Republicans’ willingness to campaign on immigration issues in the midterms, it’ll likely be a requirement for the next attorney general to uphold the increasingly nativist party line.

A bright spot, if it could even be called that, is that the turnover at the head of the Justice Department seems clearly linked to Trump’s desire to control oversight of Robert Mueller’s investigation. If enough scandal breaks over that—as it surely will—perhaps the attorney general’s office won’t be as effective as Sessions was.

Either way, it’s up to the left and to progressives to combat and reverse the Justice Department’s steady march toward tyranny. Federal courts can provide a solid check on the attorney general’s power: In August, the ACLU sued Jeff Sessions over his decision in Matter of A-B-, and the case is ongoing. But it’s hard to be optimistic with a right-wing Supreme Court sitting at the top of the judicial branch.

Congress, too, can pass laws, and a future Democratic attorney general could reverse Sessions’s worst unilateral rulings. Much of that would require a break in the Democratic tradition of reluctance in legislating immigrant and refugee rights—and a Democratic president.

As always, case workers, activists, and community organizers will be tasked with protecting asylum seekers, and helping refugees endure these dark times. We must support them as much as we can, financially and otherwise, and push for a more humane agenda to reverse Jeff Sessions’s catastrophic legacy.