President Barack Obama’s sweeping immigration executive actions will once again test the limits of his legal authority to take action without Congress.

As Obama reveals his plans in a televised prime-time address Thursday, the administration will assert that a mix of political history and court rulings give the president broad power to make policy decisions on how the nation’s immigration laws are enforced.

Obama’s case to the public will be based on three main arguments, according to White House officials and a talking points memo distributed to Democratic lawmakers.

Every president in the past 50 years, from both political parties, took executive actions on immigration. Those actions are temporary. And Supreme Court rulings and other legal precedents give the president broad “prosecutorial discretion” to enforce immigration laws when it comes to whom to deport — even if that’s for millions of Americans.

Senior White House officials said Thursday they are confident the president’s action would withstand a lawsuit, citing Supreme Court cases they say give them “nearly absolute prosecutorial discretion.”

But Republican lawmakers and other conservatives already are plotting legal attacks to reign in what they see as yet another unconstitutional overreach by Obama. They argue that Obama’s expected orders will be so broad as to unilaterally rewrite the immigration laws.

Just five months ago, the Supreme Court in a unanimous decision found Obama overstepped his authority when he used recess appointments to sidestep Congress to fill the National Labor Relations Board.

But Obama’s actions on immigration will be more difficult to challenge in court. And even if ultimately successful, lawsuits might not conclude until after Obama has left office and the administration has implemented the actions for millions of immigrants.

“Who those people are and who’s covered specifically is more of a policy question than a legal one,” said Penn State University law professor Shoba Sivaprasad Wadhia. She was among 136 law professors who wrote Obama and spelled out what she calls “a strong legal foundation” for immigration executive actions.

Legal Precedents

Obama asked Attorney General Eric H. Holder Jr. for proposals and suggestions on what the law allows him to do without Congress. At about the same time, lawyers at the Department of Justice crafted a more detailed legal justification to defend Obama’s previous immigration action in 2012.

To defend the president’s actions in court, Justice Department lawyers have seized upon language in a Supreme Court ruling from just two years ago — Arizona v. United States. That 5-3 decision focused mainly on a different issue, as the justices struck down state criminal laws in favor of federal enforcement of immigration.

But in doing so, the justices used language that some experts contend gives explicit authority to the executive branch to end deportations for millions of illegal immigrants.

The Supreme Court decision gives the executive branch discretion on deportations of individuals, but also for “policy choices that bear on this nation’s international relations,” the Justice Department lawyers highlight in the case.

It became one on the list of legal precedents the Justice Department cites in a case currently before the U.S. Court of Appeals for the 5th Circuit. It could eventually be appealed to the Supreme Court.

The government also cites a Supreme Court decision from 1999, Reno v. American Arab Anti-Discrimination Committee, and a 1976 legal opinion from the general counsel of what was then known as the Immigration and Naturalization Service that concluded that prosecutorial discretion does not depend on any specific statutory authorization.

High Hurdles

The main problem for any challengers to Obama’s immigration changes is the legal question of standing, or who has been injured by Obama’s policy change and can bring a lawsuit, constitutional law experts say.

“Coming up with a plaintiff who would be able to show an injury is not an easy thing to do in this context,” said John Malcolm, director of The Heritage Foundation’s Center for Legal and Judicial Studies. “I think there will be people who want to challenge it. I don’t know who would challenge it, and what their chances of success will be.”

Legal experts consider it unlikely that the Senate, the House of Representatives or individual members of Congress would have standing.

Even if lawmakers could establish their right to bring Obama to court over his policies, the courts have long given great deference to the executive branch on immigration. That includes the president’s decisions about how to allocate resources among competing priorities.

“We think that we would win on the merits,” said one senior White House official, should someone manage the “difficult” task of getting standing.

Still, Sen. Rand Paul, R-Ky., said this week that litigation might be the only option.

“I think the Supreme Court would strike it down, that takes a while, but that may be the only recourse short of a new president,” Paul told Fox News’ Sean Hannity.

Paul specifically cites one Supreme Court case, Youngstown Sheet & Tube Co. v. Sawyer, “where the Supreme Court actually overturned an executive order and said that the president cannot expressly do something that Congress is telling them not to do.”

That case, however, illustrates another challenge for any lawsuit against Obama. In it, the Supreme Court ruled President Harry Truman could not seize and operate most of the nation’s steel mills during the Korean War. The steel mills had something taken away from them, giving them an injury that would give them standing. With immigration, Obama isn’t taking anything away from anyone — he’s giving them something.

Republicans say that Obama’s unilateral action is more than bad policy — it’s contrary to the rule of law. Sen. Charles E. Grassley took to the Senate floor Wednesday night to lay out his case against the administration, including the release of senior-level Taliban commanders from Guantanamo without notifying Congress.

“The Office of Legal Counsel doesn’t appear to be providing independent legal advice to the President — it’s simply rubber-stamping whatever he wants to do,” Grassley said.

“It’s unconstitutional for the executive branch to nullify, or even unilaterally re-write, the immigration laws that the people of the United States, through their elected representatives, have chosen to enact,” Grassley said.

There is more chatter about a possible lawsuit from the House. Rep. Mo Brooks, R-Ala., introduced legislation Monday (HR 757) that would allow Congress to file a lawsuit. Nine Republican lawmakers co-sponsored the bill as of Wednesday.

“Seeking judicial guidance is not partisan, there is a bigger issue at stake,” Brooks said in announcing the bill. “The overarching issue in this litigation is the delicate balance of power that our nation’s founders embodied in our Constitution. Embodied in that overarching issue is one question: Is America based on tyranny or democracy?”