Though a lot of attention will be on attorney general nominee William Barr’s stance on executive power, and how it could affect the Mueller investigation, during the Senate confirmation hearings starting today, his legacy on immigration also merits strict scrutiny. Since he likely will be confirmed, Barr’s hard-line immigration stance, which runs lockstep with President Donald Trump’s, may set the stage for a new volley of attacks against immigrants and asylum-seekers. Migrants, attorneys, and advocates should be prepared.

Although former Attorney General Jeff Sessions was a hawk as well, Barr has a history of implementation that Sessions didn’t have. He also seems less inclined to tighten the reins on the president’s fervid agenda. As Sarah Pierce, policy analyst at Migration Policy Institute, told me, Barr would “fit in perfectly with this administration’s immigration priorities.”

A maximalist in his views of executive power — he’s in favor of torture, doesn’t believe that Congress should restrict a president’s power to control independent oversight commissions, and thinks that a president hardly needs to consult anybody to engage in acts of war — if he is confirmed, Barr may be the kind of enabler Trump desires to further skirt Congress and, through emergency decree or executive action, fund a border wall, continue to gut asylum protections, and keep rounding up, detaining, and deporting tens of thousands of migrants. None of these actions would be a first for William Barr.

A former CIA analyst and White House counsel under Ronald Reagan, Barr served as deputy attorney general and then attorney general to George H.W. Bush from 1991 to 1993, overseeing immigration policy moves that the Trump administration has already leaned on to implement its agenda. Before the creation of the Department of Homeland Security, the attorney general directly oversaw Immigration and Naturalization Services (the former parent agency of both the Border Patrol and INS interior enforcement, which would become ICE), and so we have an unusually clear idea of how Barr could affect immigration policy — on the border, in the interior, and in the courts.

For over a decade, throughout the 1980s, Haitians had been detained on the U.S. Naval Base at Guantánamo Bay, though they were still ostensibly granted the chance to apply for asylum. After a 1991 coup on the island, deposing the country’s first democratically elected president, conditions quickly worsened and sent tens of thousands of Haitians fleeing to U.S. shores in hopes of finding protection. Many of them were blocked by Coast Guard cutters and sent directly back to Haiti or interned for a period at Gitmo. While the State Department deployed agents onto the ships to conduct asylum screenings, an overwhelming majority of them were deemed ineligible. In 1992, as conditions in Haiti had hardly improved and many continued to leave the island, in an attempt to further stem the flow of asylum-seekers, Bush issued the Kennebunkport Order from his Maine vacation home, authorizing the Coast Guard to return all fleeing Haitians back to their country with no screening process at all.

The policy was challenged in court under the argument that it violated the central tenant — non-refoulement, or non-return — of both U.S. and international asylum law: that a country must not return an asylum-seeker to their country of origin if they are in danger there. In 1993, the Supreme Court, in Sale v. Haitian Centers Council, ruled 8-1 that it was constitutional, setting the grounds for Trump’s various attempts at asylum bans — including the Muslim ban, which Barr defended, as well as Trump’s recent attempts to limit asylum to those making claims at ports of entry and forcing incoming asylum-seekers to “remain in Mexico.”

In the majority opinion, Justice John Paul Stevens exonerated the U.S. of all responsibility toward asylum-seekers who were still outside U.S. territory, even if the Coast Guard cutters were blocking them from entering in the first place, a ruling that could have profound impact if Trump’s efforts to force asylum-seekers to remain in Mexico for the duration of their case is fully initiated and challenged. Further, the second Bush administration would later make an argument similar to Stevens’s — that the Constitution had a limited geographical reach — when claiming that it didn’t need to abide by the international treaty against torture when operating in Guantánamo Bay. Barr agreed.

But it wasn’t just that the Bush-Barr team was denying Haitians the chance to apply for asylum — they were holding them under deplorable conditions. The HIV ban had been in effect in the U.S. since 1987 — blocking people with HIV or AIDs from coming to the U.S. — and detainees with HIV or AIDs were held separately at Guantánamo Bay. According to Brandt Goldstein, author of “Storming the Court,” a book about the legal controversy over the detention program, quoting a Haitian asylum-seeker who was locked into the HIV/AIDs section of Gitmo: “There was no place to move. The latrines were brimming over. There was never any cool water to drink, to wet our lips. There was only water in a cistern, boiling in the hot sun. When you drank it, it gave you diarrhea.” When the abused detainees revolted, more than 300 Marines were dispatched in “Operation Take Charge.”

In a 1993 op-ed about the Sale v. Haitian Centers Council decision in the New York Times, Deborah Sontag asked, “If the United States, with the imprimatur of its highest court, appears to put the protection of its borders above its responsibilities under international law, will others be enticed to follow suit?” The answer is yes. The U.S. and other countries following U.S. lead have continued to turn their backs on both domestic and international asylum protections, leaving asylum-seekers to drown in the Mediterranean, die in the U.S. deserts, or, as with the recent cases of two young children, die in Border Patrol custody.

Although it’s not completely clear how much influence Barr had on Bush’s Kennebunkport Order — it’s likely he played a key role — Barr also oversaw some of the earliest construction of a “wall” along the U.S.-Mexico border. Bar saw it as “overkill” to build a fence along the entire 1,964-mile border, but he advocated for and succeeded in laying the groundwork for a policy that would come to be known as “Prevention Through Deterrence”: building barriers and concentrating enforcement at the parts of the border where it is easiest to cross — forcing migrants to take more remote and more dangerous routes. The policy has since resulted in the deaths of thousands of border crossers. Barr’s wall-building efforts also established key precedent for Operation Gatekeeper and Hold the Line, the first major steps toward the militarization of the U.S. border.

Barr also directly oversaw the expansion of the Border Patrol and ordered the hiring of 200 criminal investigators to combat immigration and crimes committed by “criminal aliens.” His efforts at creating a National Criminal Alien Tracking Center, which offered local law enforcement a way to contact the INS to “identify and track aliens who commit crimes” preceded much criticized programs, such as Bush’s 287(g), which deputized local police into acting as immigration agents. Barr’s Tracking Center is also eerily similar to Trump’s Victims of Immigration Crime Engagement office.

Barr even blamed the Rodney King riots on immigration, as Dara Lind notes, which foreshadowed Trump’s erroneous and malevolent claims that immigrants are to blame for violence in U.S. cities today. In fact, immigrant neighborhoods have significantly less violence and crime.

Under Trump, Sessions — as a way to issue a new ruling and influence immigration law and how immigration judges interpret the laws — certified more immigration cases to himself than any other attorney general in history. Due to the shake-up between Sessions, acting Attorney General Matthew Whitaker, and now nominee Barr, there remain four certified cases that will be waiting on the next attorney general’s desk. The decisions on those cases will have profound effects on immigration law and include whether or not asylum-seekers should be eligible for bond or will have to fight their cases from behind bars. Given his history, if Barr takes that seat, we have a good idea of how he will rule.