Many of President Donald Trump's policies have met resistance in federal courts, but anyone challenging the decision to end deportation protections for thousands of immigrants Tuesday will face a difficult legal fight.

Attorney General Jeff Sessions announced Tuesday that the Department of Homeland Security will begin a “wind down” of the Deferred Action for Childhood Arrivals program. Sessions said the administration will end the program “in light of imminent litigation,” a nod to the threat by several Republican state attorneys general to sue if Trump allowed the program to continue past Sept. 5. Now, advocates and state attorneys general are threatening legal action to keep the program in place. Legal experts said such lawsuits could be longshots.

“The reality is that DACA was announced and signed by the secretary of Homeland Security,” said Shoba Sivaprasad Wadhia, a professor at Penn State Law and director of the school's Center for Immigrants' Rights Clinic. “It is a policy document, so it is a tool in administrative law, but it can technically be rescinded, modified, replaced.”

Sessions made the announcement after he sent a letter Monday to DHS Acting Secretary Elaine Duke asking her to rescind the agency's policy because he expected potential legal challenges against the program to succeed. Wadhia said it was “stunning” the president did not appear at the press conference. She noted it was Sessions who made the announcement Tuesday, though the DACA program was originally announced by DHS.

The DACA program protects children of undocumented immigrants brought to the U.S. before their 16th birthday by granting them temporary relief from deportation, work permits and other benefits if they meet certain criteria. President Barack Obama created the program in 2012. He expanded it via executive action in 2014, creating the Deferred Action for Parents of Americans program to include parents of U.S. citizens, though DAPA was struck down by a federal district court in Texas in 2015.

That decision was subsequently upheld by the Fifth Circuit and by a tied U.S. Supreme Court in 2016. Sessions pointed to that case in his letter to DHS as evidence DACA would not withstand legal threats.

Lawsuits on the Horizon

Within hours of the decision Tuesday, lawyers from the National Immigration Law Center, known as NILC, filed a letter in an ongoing case in the Eastern District of New York explaining their intent to file an amended complaint to address the termination of DACA. Attorneys general Xavier Becerra of California, Bob Ferguson of Washington and Eric Schneiderman of New York also threatened legal action, though it's still unclear what the legal framework of those lawsuits could be.

The lawyers for NILC, along with a team from the Jerome N. Frank Legal Services Organization at Yale Law School and advocacy group Make The Road New York, wrote in their letter that the decision to rescind DACA violated the Administrative Procedure Act because the government did not offer a “reasoned explanation” for rescinding the policy.

They also claim the termination was motivated by the president's racial animus toward Latinos, evidenced by his public statements, and therefore violated the equal protection component of the Fifth Amendment's Due Process clause.

Constitutional Claims

Scholars said it's difficult to predict how courts would rule on the Fifth Amendment argument. Anthony Kreis, a visiting assistant law professor at the Chicago-Kent College of Law, said it's a tough claim to prove.

“The animus argument, I think, is a fairly strong one but it is hard to predict how receptive courts will be to it,” Kreis said in an email. “It isn't terribly clear the extent of what constitutional constraints there are on the government's authority to regulate immigration, so it is anyone's guess how this might turn out assuming Congress doesn't take action.”

The Fifth Amendment argument echoes the one raised in ongoing litigation over the president's travel ban executive order, scheduled for argument before the Supreme Court in October, several scholars pointed out. In that case, two circuit courts ruled the president's comments about banning Muslim immigrants could plausibly be evidence Trump intended to discriminate based on religion.