It’s been a busy week for Jeff Sessions. The US attorney general is deploying his broad powers to remake the US’s immigration system instead of waiting for Congress to pass legislation.

Late Tuesday, he filed a lawsuit against the state of California, for its policies limiting cooperation between state officers and federal immigration agents. ”Federal law is the supreme law of the land,” he said in a speech in Sacramento on Wednesday.

Far more quietly, on Monday, Sessions took the unusual step of digging up an old legal decision that affirmed asylum-seekers’ right to a make their case in court—and cancelled it. That little-noticed move has the potential of doing more to further Trump’s efforts to deport undocumented immigrants than his attack on so-called sanctuary jurisdictions like California.

Sessions’s choice to revisit the four-year-old case on Monday was not explained in his three-paragraph announcement. A Justice Department spokesperson tells Quartz that the decision which Session overruled had “added unnecessary cases to the dockets of immigration judges, who are working hard to reduce an already large immigration court backlog.”

The mountain of pending immigration cases, which now stands at nearly 670,000, has emerged as a major bottleneck for Trump’s administration. Regardless of their legal status, many immigrants are entitled to a day in court under the law. With US immigration courts chronically understaffed, that can take years. Many applications will likely be processed more quickly—and denied—if asylum-seekers aren’t given the chance to argue their case.

The Matter of E-F-H-L

As head of the Department of Justice, Sessions oversees the country’s immigration courts, and the Board of Immigration Appeals (BIA,) where parties can contest immigration judge decisions. Unlike federal or state courts, the immigration court system is not part of an independent judicial branch, but embedded within a president’s administration.

Critics—including many immigration judges—say that setup makes the court system vulnerable to political interference, and there’s evidence that both Democratic and Republican administrations have done that to further their goals.

Among the attorney general’s powers is the ability to single-handedly overwrite any decisions by the BIA, as Sessions did on Monday. The decision he is zeroing in on is related to a case dubbed “Matter of E-F-H-L,” after the initials of the person who brought it to the appellate body. E-F-H-L, a Honduran immigrant, requested asylum. He appeared before an immigration court, but didn’t get a chance to testify because the judge determined E-F-H-L had no chance of getting asylum based on his application.

E-F-H-L appealed the decision to the BIA, which found that the judge had dismissed the case prematurely. An asylum applicant, it said in its decision, “is entitled to a hearing on the merits of the applications, including an opportunity to provide oral testimony and other evidence.” By striking it, Sessions is signaling that giving asylum seekers that chance is no longer required.

Paul Schmidt, a former immigration judge, says it’s important to hear out asylum applicants even if their case doesn’t look very solid on paper. Many of them—around 20% whose cases were decided in fiscal 2017—don’t have a lawyer, and are not familiar with the kind of information that should be included in the application. Others don’t even speak English. “You can’t always tell how the case is coming out just by looking at the application,” he said.

But another retired immigration judge, Andrew Arthur, welcomed the apparent change. “Given the fact that an asylum merits case can take anywhere between two hours and several days, this authority will allow those judges to streamline their dockets and complete more cases in a timely manner,” he wrote in a post for the Center for Immigration Studies, a think tank that advocates for reducing undocumented immigration.

Sessions’s decision also appears to target the asylum system in particular, which he’s said is being gamed by people with false claims. The precedent it sets is bound to make it more difficult for asylum seekers to make their case.

Administrative closure

Sessions’s sudden interest in E-F-H-L also appears to be related to a tool immigration judges often use referred to as “administrative closure.” That’s when a judge decides to put a case on the back burner instead of immediately deciding whether a person can stay in the US or should be deported.

There are several reasons why judges might delay a case’s decision. Sometimes rescheduling helps them organize their crowded docket; other times an immigrant may be in the middle of a visa application with US Citizen and Immigration Services, in which case it makes sense to wait until that process is completed, says Lenni Benson, a professor at New York Law School.

That appears to have been E-F-H-L’s case. In its decision, the BIA ordered the judge to give E-F-H-L a proper hearing, but by that time, he had applied for a family-based visa and didn’t want to follow through on his asylum claim. So the judge put the case in administrative closure. In his Monday decision, Sessions argued that since the immigrant is no longer applying for asylum, his case should be put back on the docket and resolved.

It seems odd that the head of the Justice Department would make time in his busy schedule to single out an obscure four-year-old case. But Benson says it fits within a broader effort to remove judges’ ability to put a case on hold.

Earlier this year, Sessions used his authority to pluck another case, this one involving a Guatemalan minor, to question the use of administrative closure. He is currently asking for input before taking any action, however. (Several groups, including the Safe Passage Project, a non-profit where Benson runs a program to train pro bono lawyers to represent immigrant youth, have filed a brief advocating for Sessions to keep the practice.)

If he doesn’t, the group of affected immigrants would be much broader than just asylum seekers. The use of administrative closure expanded during the Obama presidency. Because that administration’s focus was on criminals, the cases of many undocumented immigrants with a clean record became lower priorities. Administrative closure essentially took those immigrants off the list of deportation targets, even if their legal status remained unchanged.

The Trump administration, however, has made it clear it’s going after everyone who is in the country illegally. With efforts to change immigration law stalled in Congress, Sessions appears to be doing everything he can administratively to carry out Donald Trump’s vision.