Unauthorized immigration should be decriminalized, California Attorney General Xavier Becerra (D) said in an interview with HuffPost on Friday, becoming one of the few prominent Democrats to challenge a key aspect of the Trump administration’s crackdown.

“They are not criminals,” Becerra said of migrants who cross without authorization. “They haven’t committed a crime against someone, and they are not acting violently or in a way that’s harmful to people. And I would argue they are not harming people indirectly either.”

The remarks from California’s top law enforcement officer are rare even from a Democratic politician, although the idea is picking up steam. This week, Democratic presidential candidate Julián Castro proposed repealing the code that makes illegal entry a criminal offense in addition to a civil one; fellow presidentialhopeful Beto O’Rourke has said we should do the same for asylum-seekers and families. Reps. Raúl Grijalva (D-Ariz.) and Veronica Escobar (D-Texas) have also told HuffPost that immigration should be decriminalized.

For the most part, Democrats have decried the results of criminalizing immigration — such as the mass separations of immigrant families as President Donald Trump ramped up prosecutions last year — without criticizing the underlying law that made the separations possible.

Decriminalizing immigration wouldn’t mean that crossing the border without authorization would go unpunished. Becerra acknowledged that those who do so violate civil laws and skirt the normal process for entering. But criminally charging people with immigration violations in addition to putting them through deportation proceedings serves to brand migrants as criminals, he said, whether or not they commit acts of violence or property crimes.

“If you call them criminals, it’s a lot easier to get people to turn against them than if you call them undocumented immigrants,” Becerra said.

Bringing criminal charges against unauthorized border crossers is largely redundant. Virtually everyone convicted of illegal entry or re-entry gets shunted from federal criminal custody to Immigration and Customs Enforcement to face deportation proceedings. But advocates of the system insist that leveling criminal penalties on top of civil ones deters migrants from crossing.

Congress criminalized the act of jumping the border in 1929, passing a law spearheaded by Sen. Coleman Blease ― an avowed segregationist known for performing ritual dances to celebrate the lynchings of black men. The law, which was incorporated into the Immigration and Nationality Act of 1952, laid the basis for the early expansion of the federal prison system, according to research by UCLA professor and historian Kelly Lytle Hernández.

Under current law, the first illegal entry into the United States is a misdemeanor punishable by up to six months in prison. Subsequent violations can be prosecuted as felonies, with sentences ranging up to 20 years in prison, depending on migrants’ criminal histories, though in practice most offenders receive far shorter sentences.

Under George W. Bush’s administration, immigration prosecutions began a massive expansion. At the time, large numbers of Central American migrants were crossing through the Del Rio sector of Texas. When Immigration and Customs Enforcement ran out of bed space to detain them, the Department of Homeland Security teamed up with the Justice Department to systematically file prosecutions against migrants for illegal entry, allowing federal authorities to lock them up in jails run by the U.S. Marshals Service instead of releasing them with notices to appear in immigration court.

The Bush administration expanded that 2005 program, known as Operation Streamline, across much of the rest of the border. By 2008, immigration prosecutions had swallowed up roughly half the federal criminal docket.

The system, which continued under President Barack Obama, left America’s first black president with the unexpected legacy of having locked up more people of color on criminal charges than any other president in modern U.S. history.

It also handed Trump a potent weapon to use for his promised crackdown on illegal immigration. On Friday he threatened to shut down the southwestern border if Mexico doesn’t stop illegal entries.

The Trump administration filed more than 94,000 prosecutions for illegal entry or re-entry last year, according to the Transactional Record Access Clearinghouse database at Syracuse University, topping the record set by Obama in 2013. The two charges accounted for 57 percent of the federal criminal docket in 2018.

The federal government’s myopic focus on immigration prosecutions has come at a cost. Prosecutions for white collar crimes have plummeted by 40 percent over the last 20 years, according to TRAC, even though that period encompasses the fraud-fueled economic crisis that began in December 2007.