By Bob Egelko

A group of Democratic-led states is leading a legal challenge to President Trump's planned repeal of a program allowing nearly 800,000 young undocumented immigrants to remain in the United States -- and just as in the court fight over the president's proposed travel ban, the challengers want to use his ethnic broadsides against him.

In a lawsuit filed Wednesday, lawyers for New York, 14 other states and the District of Columbia cited government data showing that under the program that Trump is seeking to end -- Deferred Action for Childhood Arrivals, or DACA -- 78 percent of the immigrants gaining reprieves from deportation have been of Mexican origin.

Mexico, the suit noted, was also featured in the opening salvo of Trump's presidential campaign in 2015, when he declared that immigrants from that country were "bringing drugs. They're bringing crime. They're rapists."

He said during one presidential debate that Mexican authorities "send the bad ones over because they don't want to pay for them," and in another debate that he planned to deport "some bad hombres." Last year, he labeled as Mexican a U.S.-born federal judge whose parents emigrated legally from Mexico, and accused the judge of being biased against him in a civil case because Trump wants to build a wall at the border.

"The president has demonstrated a willingness to disparage Mexicans in a misguided attempt to secure support from his constituency," the states said in a suit filed in federal court in New York. The "culmination" of that disparagement, the suit said, would be "ending DACA, whose participants are mostly of Mexican origin."

In other words, they argued, although neither DACA nor Trump's order to abolish it singles out any race or nationality, his intent was to exclude Mexicans, in violation of the constitutional guarantee of equal protection of the laws.

It's reminiscent of the argument that some of the same states have used to challenge Trump's ban on U.S. entry of anyone from six nations with mostly Muslim populations: that he revealed his intent in campaign promises to halt Muslim immigration and in a reported request to a presidential adviser to find a legal way to ban Muslims. The argument has won favor with a series of federal courts, but the U.S. Supreme Court will have the final say after a hearing in October.

"The president's intent (in his DACA order) was demonstrated by his comments. ... That (argument) does have some appeal" and might persuade the courts, said Bill Ong Hing, an immigration law professor at the University of San Francisco.

Another immigration law professor, Pratheepan Gulasekaram of Santa Clara University, said the states' argument was weaker in the DACA case.

"You don't have the direct connection between the statements and the rescission of DACA" that existed in the travel ban, Gulasekaram said. And unlike the earlier case, he said, Trump's lawyers could also point to sympathetic comments he has made about Mexicans and DACA recipients.

But even if the states can't show that Trump's disparaging remarks proved a discriminatory motive, Gulasekaram said, they could provide a "counter-narrative" to Attorney General Jeff Sessions, who described the president's actions as steps to save American jobs and protect the public.

The suit comes a day after Trump announced that he would phase out DACA, starting in March, unless the Republican-controlled Congress enacts a law authorizing the program.

President Barack Obama established the program by executive order in 2012, allowing "Dreamers" -- immigrants who had entered the U.S. without authorization before age 16, and had no serious criminal records -- to apply for renewable two-year reprieves from deportation and work permits.

About 230,000 people in California are among those enrolled in DACA. California's attorney general, Xavier Becerra, said Tuesday that he would also sue to overturn Trump's order, but the state has not joined the New York lawsuit. Becerra's office did not respond to inquiries Wednesday.

The other states taking part in the suit -- all with Democratic attorneys general -- are: Connecticut, Delaware, Hawaii, Illinois, Iowa, Massachusetts, New Mexico, North Carolina, Oregon, Pennsylvania, Rhode Island, Vermont, Virginia and Washington. Each state argued in court papers that repealing DACA would harm thousands of residents, damage their public universities and workplaces, and hurt their economies -- all of which is evidence of the direct impact needed for the right to sue.

In addition, they said, the federal government induced DACA applicants to provide personal identifying information that could be used to locate and deport them. They noted that Trump signed an executive order in January allowing federal agencies to share immigration information with law enforcement agencies.

The suit also contends Trump's order amounts to a change in federal regulations that must be submitted for public notice and comment before it can take effect. A federal judge in Texas relied on a similar argument in 2015 to invalidate Obama's attempt to grant reprieves from deportation to several million parents of U.S. citizens and legal residents.

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