The Obama administration on Thursday took the unprecedented step of creating obstacles to a widely-anticipated but poorly understood plan by President-elect Donald Trump to establish a Muslim ban or registry — by dismantling the registry system that already exists.

The Department of Homeland Security issued a “final rule” to formally dismantle the regulatory framework for the National Security Entry-Exit Registration System (NSEERS), a preexisting government program that was used to register and monitor visitors from “high-risk” countries from 2002 to 2011.

Civil rights advocates, who have been calling for such action, say the program, enacted under former president George W. Bush, already amounted to a registry for Muslims through discriminatory targeting. Obama shelved the program in 2011, but the regulations that allow it to function were never dismantled.

Kansas Secretary of State Kris Kobach, who helped the Bush administration create the program after the 9/11 terrorist attacks and now advises Trump, has been photographed holding a proposal for NSEERS’s reinstatement while meeting with Trump.

The move is the latest in a string of recent efforts by the Obama administration to safeguard current policies and Democratic values that they expect Trump to target. Last week, the Department of Health and Human Services finalized a regulation to block discrimination against Planned Parenthood in the allocation of federal grants, and on Tuesday, the president announced a ban on offshore oil and gas drilling in areas of the Arctic and the Atlantic Ocean.

The Department of Homeland Security said Thursday that it was removing the “outdated regulations” that allowed the program to function.

“The Department of Homeland Security is removing outdated regulations relating to an obsolete special registration program for certain nonimmigrants,” the agency said Thursday in a document first reported by the New York Times and confirmed by the agency.

The program’s end was a long time coming.

“NSEERS was a huge waste of time, money. But no one remembers it. Everyone talks about a Muslim registry, but we had one,” said Mirriam Seddiq, a criminal defense and immigration attorney.

Civil rights activists and immigration attorneys say the program disproportionately targeted Muslim men.

The program mandated that men over the age of 16 from one of 25 countries on a list were required to register if they were living in the United States. Twenty-four of those countries were Muslim majority countries.

Registration, which involved fingerprinting, interrogations and sometimes parole-like check-ins, was required, regardless whether the people had broken the law.

Those men who overstayed their visas or failed to comply with annual registration requirements or more frequent check-ins were deported.

Nearly 180,000 people registered with the program when it was in place; more than 83,500 of them were already residing in the United States when the program was enacted.

Activists from and smaller groups, who staged a protest against NSEERS outside the Justice Department last week, say that 13,000 of them were deported — claims that the Department of Homeland Security have neither confirmed nor denied.

The DHS inspector general in 2012 recommended abandoning it on the grounds that it was “inefficient and ineffective.” But, said a senior U.S. official, who spoke on condition of anonymity to discuss internal deliberations, “with the heat of the rhetoric of a Muslim registry, with the hyper-politicization of religious tests as a kind of purity filter and patriotism filter, a renewed, energized push was begun” to get rid of it.

The push was supported by senior administration officials and career civil servants alike across the government, from the White House to DHS to the Justice Department to the FBI and the intelligence community, several senior U.S. officials said.

“This is huge,” said Elizabeith Goitein, co-director of the Brennan Center for Justice’s Liberty and National Security Program. “It’s not going to prevent Donald Trump from trying to institute a Muslim registry, but it will make the process longer and harder. It also sends an important signal to Muslim American communities that they shouldn’t be treated differently, that they shouldn’t be signaled out as automatically suspect.”

Trump’s transition team did not respond Thursday to a request for comment on the measure, and to clarify its intentions in regards to a registry or ban.

Asked by reporters about the ban proposal Wednesday, Trump appeared to reaffirm his commitment to the idea, saying: “You know my plans all along.”

His former campaign manager and newly-named White House counselor Kellyanne Conway then told CNN Thursday morning that Trump would not pursue a ban based on religion but rather on country of origin. The incoming administration’s website also contains conflicting statements on this subject.

Experts say if Trump wanted to relaunch NSEERS, he could do by having the Department of Homeland Security issue a new administrative rule, which would require a public comments period, which tend to last 30 to 60 days, said Naureen Shah, the director of the Security and Human Rights program at Amnesty International USA, and would likely invite litigation by civil rights attorneys, on the grounds that the program would be discriminatory, in violation of the constitution.