WASHINGTON — The head of the leading Latino legal civil rights group called on President Donald Trump Monday to ignore a Sept. 5 deadline set by 10 attorneys generals to decide whether to end the Deferred Action for Childhood Arrivals, or DACA, program.

Thomas Saenz, president of the Mexican American Legal Defense and Organizational Fund, said Trump can tell Texas to “pound sand” regarding their threat to sue over the 2012 DACA program.

Because DACA has been in place five years, has been successful and has resulted in economic benefit for Texas, the attorneys general face a tough legal burden to get an immediate halt to the program, he said.

“The president has the authority to rescind (DACA) at any time. There is no reason for him to act before an arbitrary deadline,” Saenz said.

There is some expectation Trump will act soon to end DACA, affecting some 1 million people. The program has allowed about 800,000 young people who arrived or stayed illegally in the U.S. to remain in the country and work.

“If he caves into the deadline, it is, in my view, a tremendous concession of weakness,” Saenz said. “He’s supposedly a tough negotiator in business, foreign government, with Congress, but apparently with the state of Texas, he caves in. So this is the time for him to show his tough negotiating skills, to tell Texas to pound sand and then proceed to negotiate something that will protect group of immigrants worthy of protecting. He said that recently.”

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The attorneys general sued the Obama administration last year over another deportation deferral and work permission program, known as DAPA, for parents of U.S. citizen and legal immigrant children. The suit also challenged an expansion of the 2012 DACA. The attorneys general want to convert the lawsuit into a challenge of the 2012 DACA program.

But Saenz said to do so they have to show that Texas has suffered some injury from the program. They'll have to show that the costs of the DACA recipients to the state outweighed the benefits that resulted from allowing them to work and pay taxes, buy homes and other consumer goods.

"I think they’ve got a pretty tough tough road to go down if they want to establish standing for purposes of challenging DACA" in court, Saenz said.

Related: 'Dreamers' Fear Trump Immigration Crackdown as DACA Hits 5th Anniversary

Trump has previously expressed compassion for young people with DACA, but he has been pressured by the attorneys general and far right conservatives to phase out or rescind DACA.

Authorized by former President Barack Obama by executive action, the 2012 program has been dubbed unconstitutional by its opponents who are holding Trump to a campaign pledge to rescind all Obama’s executive actions.

California Attorney General Xavier Becerra, a Democrat, wrote a letter with 20 other attorneys general urging him to continue DACA. In a telephone news conference Monday, Becerra pointed to the collective efforts in Texas to respond to the flooding following Hurricane Harvey and to respond to the damage.

“We speak on this issue when so many Americans are going through such a tough time in Texas … I have no doubt among them will be families who have DACA recipients in them,” he said. “This is a time when we all come together … It makes no difference where you came from, what you look like, when a disaster strikes, Americans come together.”

Related: Anniversary of DACA Deportation Protection Marked By Fear They're Ending

Democratic Party Chairman Tom Perez recalled that he defended DACA while serving as assistant attorney general over the civil rights division in the Department of Justice. He said he has great confidence that DACA is on solid legal footing.

“Our party is going to fight tooth and nail to fight to protect this program,” he said.

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