"Basically the President has stepped in and taken over what normally would be associated with Congress," Texas Attorney General Ken Paxton said in an interview. "Congress makes the laws."
The GOP Congress will be involved at oral arguments as well. The House of Representatives, in an unusual move, intervened in the case against the administration, and will have 15 minutes before the eight justices to argue its case Monday.
That only eight justices are hearing the case -- due to the death in February of Justice Antonin Scalia -- could impact the final result. A split court between the four Democratic-appointed justices and four GOP-appointed justices would mean the programs remain blocked and the case is sent back to the district court in Texas that blocked them in the first place.
For the administration, a key argument before the court is to say that the states do not have the legal right to bring the case in the first place. If it can convince a majority of justices on that issue, the court may not even get to the merits of the immigration debate.
Should it win on that count, the injunction would be lifted, and the programs would be able to go into effect during the final months of the Obama presidency.
However, because the actions can be changed or reversed by the next President, immigrants would have to decide whether to come forward for the remaining months of the Obama administration or risk doing so with the possibility of Donald Trump or Ted Cruz in the White House.
"There's no question that the ultimate fate of the deferred action policy hangs in the balance of the upcoming election," said Stephen I. Vladeck, a professor of law at American University and CNN Legal Analyst.
"Like any other executive order, it can be modified, rescinded, or expanded by the next President, and codified or overruled by the next Congress," he added. "But the fact that the Supreme Court expedited its consideration of the Obama administration's appeal so that it could resolve the dispute by June suggests that, even short-handed, the justices want to have their own say first."
The White House announced the programs in November 2014, issuing a five-page guidance memo enabling qualifying undocumented workers to receive temporary relief from the threat of deportation and to apply for programs that could qualify them for work authorization and associated benefits.
The Deferred Action for Parents of Americans and Lawful Permanent Residents (DAPA) targets the nearly 4.3 million undocumented parents of citizens and lawful residents, and the second rule expands Deferred Action for Childhood Arrivals (DACA), initiative aimed at non citizens who came to the country as children.
"We'll bring more undocumented immigrants out of the shadows so they can play by the rules, pay their full share of taxes, pass a criminal background check and get right with the law," Obama told an audience in Nevada after the programs were announced.
The programs remain frozen nationwide. They were first blocked by a federal judge in Texas and a divided federal appeals court later upheld the preliminary injunction.
Obama's lawyers argue in court papers that the lower court rulings threatened great harm, "not only to the proper role of federal courts and to federal immigration law, but also to millions of parents of U.S. citizens and permanent residents, aliens who are the lowest priorities for removal yet now work off the books to support their families."
As a threshold issue, Solicitor General Donald Verrilli says that the states don't have the legal right to be in court, because the Constitution "assigns the formation of immigration policy exclusively to the National Government precisely because immigration is an inherently national matter."
He stressed that the guidance from the government does not provide any kind of lawful status under immigration law as the aliens remain removable at any time.
"Immigrant communities fought for these programs," said Marielena Hincapié, the executive director of the National Immigration Law Center. She says that her groups have been informing people about the risks of the rules being changed by the next president and she believes many will come forward should the Obama administration win.
Texas Solicitor General Scott Keller argues that the states have standing to bring the challenge in part because DAPA would create a new class of recipients for state subsidized driver's licenses in Texas. He says that Texas would stand to lose millions of dollars if even a small fraction of DAPA eligible aliens applied.
"DAPA is an extraordinary assertion of executive power," Keller wrote in court papers. "The Executive has unilaterally crafted an enormous program -- one of the largest changes ever to our Nation's approach to immigration," he said. "In doing so, the Executive dispensed with immigration statutes by declaring unlawful conduct to be lawful."
He points to the guidance and says that the eligible undocumented immigrations would be permitted to be "lawfully present in the United States," which would make them eligible for work authorization and some types of Social Security and Medicare benefits.
Texas is supported by the GOP-led House of Representatives, who say that the programs went forward after the President failed in his attempts to persuade Congress to revise immigration laws.
Erin E. Murphy, a lawyer for the House, called the administration's position, "the most aggressive of executive power claims."
But Vladeck says standing is where justices may look to find a path forward.
"Because the justices will want to avoid a 4-4 tie if at all possible, there's a more than decent chance that they'll gravitate toward the standing issue, and hold that any injury suffered by Texas is its own fault, since nothing requires the state to subsidize driver's licenses -- and to thereby incur the costs on which it is relying.
"And such a holding might unite the liberal and conservative justices, the former of whom would want to see the program survive, and the latter of whom typically favor narrower standing rules," he added.
Andrew Pincus, a lawyer who supports the administration's position, says that allowing Texas to bring the case would have broad implications.
"If a state can sue every time the federal government does something to increase the state's costs, states could sue to challenge almost anything the federal government does," he said.
Pincus points out that Texas is not objecting to the administration's use of prosecutorial discretion, it just doesn't want the undocumented workers to be able to work legally.
"You are saying to these people, you can stay here, but we are keeping you in a bubble," he said.
