Las Vegas (AP) – As thousands of children were taken from their parents at the southern border during a Trump administration crackdown on illegal crossings, a federal public defender in San Diego set out to find new strategies to go after the longstanding deportation law fueling the family separations.

The resulting legal defense that Kara Hartzler would help draft in the coming years work that continued even after a judge halted the general practice at the U.S.-Mexico border in June 2018 was unprecedented.

It exposed Section 1326 of the Immigration and Nationality Act, which makes it a crime to unlawfully return to the U.S. after deportation, removal or denied admission, as racist and a violation of equal protection rights guaranteed by the Fifth Amendment.

And it became the legal framework for a never-before-seen ruling in August 2021 by Nevada U.S. District Judge Miranda Du. She struck down the law as unconstitutional and discriminatory against Latinos when she dismissed an illegal reentry charge against Mexican immigrant Gustavo Carrillo Lopez, though she didn’t block enforcement and prosecutions haven’t stopped as the government appeals the case.

Du’s 43-page ruling cited much of Hartzler’s legal defense. “The record before the Court reflects that at no point has Congress confronted the racist, nativist roots of Section 1326,” the judge wrote.

Hartzler, who has spent the last decade as a federal public defender in California, said she was blown away when she learned of the ruling.

“When you’ve been working in law for as long as I have, you know that just because you’re legally right doesn’t mean you always win,” she said. “There’s a lot of forces at work in making legal decisions.”

The potentially precedent-setting case has been in legal limbo for more than a year as a federal court in California considers the Justice Department’s appeal defending the law. Despite the ongoing battle in the 9th Circuit Court of Appeals, the Nevada case has shined a national spotlight on the little-known history of Section 1326.

“It really is an ill-understood law when you think about the degree to which it is based on explicitly racist and white supremacist ideology,” said Sirine Shebaya, executive director of the nonprofit National Immigration Project.

Section 1326, along with its misdemeanor counterpart Section 1325, which criminalizes unauthorized entry, was enacted by Congress in 1952.

But the law’s origins can be traced back a century to the 1920s – a decade described by UCLA history professor and leading Section 1326 researcher Kelly Lytle Hernandez as “a time when the Ku Klux Klan was reborn, Jim Crow came of age, and public intellectuals preached the science of eugenics.”

Many of the key elements that formed the legal defense now being considered by the 9th Circuit came from Hernandez’s findings on Section 1326’s discriminatory background.

With Congress’ sights in the 1920s set on legislation that would block “undesirable” immigration, the National Origins Act of 1924 was enacted, establishing a cap on how many immigrants could enter the U.S. under a system that reserved 96% of slots for European immigrants and included a total ban on Asian immigrants.

Exempt from that system, however, were immigrants from the Western Hemisphere, including Mexico. Hernandez, who was called as an expert witness in the Nevada case, said the exception came as a compromise between nativist lawmakers and employers who had come to rely heavily on cheap labor from Mexico.

But before the decade’s end, South Carolina Sen. Coleman Livingston Blease would orchestrate a new deal with employers that led to the Undesirable Aliens Act of 1929.

Under this new law, unauthorized entry into the U.S. became illegal, allowing Congress to limit immigration from Mexico without implementing an outright ban.

Blease, Hernandez said, was a “proud white supremacist” who advocated for segregation and defended lynching. “That alone requires some reckoning with.”

Nearly a century later, the Justice Department has conceded that the 1929 law was motivated by racism. But in oral arguments in early December before the 9th Circuit, an attorney for the U.S. government argued later revisions – like Section 1326 – made it constitutional.

Du’s ruling, however, points out that the 1952 revision establishing Section 1326 had adopted language “word for word” from the 1929 legislation, and since then, penalties – that range from prison time to permanent deportation – have stiffened at least five times.