A law professor bashed Stephen Miller for pushing discriminatory immigration restrictions in America that have long been gone.

Miller, the Trump administration's immigrant policy architect and Homeland Security Advisor, has tried to revive "nationality-based discrimination" policies that formally embarrassed the United States, Amanda Frost, a University of Virginia law professor who specializes in immigration law, wrote in an opinion piece for The New York Times published Friday.

The Trump administration announced that it has "indefinitely" stopped immigration policies for all Afghan nationals after a Nov. 26 National Guard shooting involving an Afghan suspect who shot two troops — one fatally — in Washington, D.C.

Frost slammed Miller's harsh immigration policy and described how it harkened to the "nativist fervor culminated in 1924 with the Immigration Act," which aimed to try and slow down immigration from countries that were deemed "undesirable." It capped immigration to make it 2% of the nationality's population in the U.S. in 1890.

"It proved impossible to unwind Americans’ tangled ancestry, but no matter. The law was used to justify giving the majority of visas to Northern and Western Europeans, while strictly limiting immigration from Southern and Eastern Europe — a change celebrated by the Ku Klux Klan for keeping out Catholics and Jews. The door remained almost entirely closed to people from Asia and Africa," Frost wrote.

Miller has appeared to make a similar move in his response to immigration.

"Mr. Miller and others in the Trump administration do not appear to know that those 1924 immigration restrictions are no longer on the books. Abolishing national origin discrimination was a sea change in law that stands alongside the Voting Rights Act as one of our most important pieces of civil rights legislation," Frost explained. "That 1965 law allocated visas based primarily on family reunification and an applicant’s ability to contribute to the labor market. Every immigrant is individually vetted, and immigration is capped worldwide, but no longer are any nationalities automatically restricted."

The writer argued that the suspect should be investigated and punished if he is found guilty of the attack.

"But collective punishment is just the sort of bigotry that the nation rejected decades ago," Frost added.

"It’s also likely to be illegal. As the Supreme Court explained when upholding Mr. Trump’s first travel ban back in 2018, the president has statutory authority to suspend entry into the United States based on national origin, at least for some period of time. But that does not permit him to deny visas, cancel green cards or denaturalize immigrants based on nothing more than their country of origin," Frost wrote.