In this February 2020 photo, then-President Donald Trump greets Supreme Court Chief Justice John Roberts as he arrives to deliver his State of the Union address in Washington, DC.
CNN  — 

The roiling debate over the strength of democratic restraints to keep Donald Trump in check when he returns to the White House in January has put a renewed focus on a divisive Supreme Court ruling that some fear could enable his worst impulses.

Trump’s sweeping election victory has relit fears on the left of an empowered president pushing the boundaries of his authority – only now with a precedent in hand that grants far-reaching immunity from criminal prosecution.

Taken together, the political and legal alignment will usher Trump into a second term with unprecedented power following a campaign in which he vowed to fire special counsel Jack Smith “within two seconds” of his inauguration and has flirted with the idea that President Joe Biden himself “could be a convicted felon.”

“For 250 years, the possibility of criminal prosecution operated as a guard rail on the conduct of our presidents,” said Neil Eggleston, a veteran attorney who served as White House counsel in the Obama administration. “That guard rail is now gone, and I see few if any others that will constrain President Trump.”

In a highly anticipated ruling on July 1 that came over the objection of the three-justice liberal wing, the Supreme Court held that Trump enjoyed “absolute” immunity from prosecution for actions taken within his core constitutional powers and a more limited immunity for other official actions.

Chief Justice John Roberts wrote that Congress couldn’t criminalize a president’s conduct when he is “carrying out the responsibilities of the executive branch.”

Based on their statements at oral argument, it was clear that several conservative justices saw the ruling not as a gift to Trump but rather as a way to head off spiraling and potentially politically motivated prosecutions. And while the decision may accomplish that – complicating any effort to prosecute Biden once he leaves office, for instance – it is also widely viewed as removing a check on a president who chafed at the concept of boundaries.

Justice Sonia Sotomayor warned in her dissent that the decision would set up future presidents to be “a king above the law.” Noting an often-quoted hypothetical about Navy SEALs being ordered to kill political opponents, Sotomayor relayed worst-case scenarios.

“Orders the Navy’s Seal Team 6 to assassinate a political rival? Immune,” she wrote. “Organizes a military coup to hold onto power? Immune. Takes a bribe in exchange for a pardon? Immune. Immune, immune, immune.”

Justice Department ‘problem’

But just how far that immunity extends is murky. The Supreme Court’s 6-3 decision left many questions unanswered and lower courts have not yet wrestled with them. And they may not get the chance: Within hours of Trump winning, Smith was discussing with Justice Department officials how to wind down the federal cases against him.

It’s not likely that Trump or anyone else will have a firm sense by January of what constitutes “official actions” that are entitled to immunity, for instance. It is doubtful that the White House or prosecutors will know for certain when they can overcome the “presumptive immunity” the Supreme Court said applies to most of a president’s actions. It’s also not clear how the court defines the “core” constitutional functions of a president that the opinion said are entitled to “absolute immunity.”

Much of that analysis, the majority wrote, “is best left to the lower courts.”

What is exceptionally clear in the Supreme Court’s ruling from July is the notion that a president’s discussions with Justice Department officials are completely immune from prosecution. Smith’s first indictment in the election subversion case alleged Trump pressured Justice Department officials to “conduct sham election crime investigations” and send letters to states falsely claiming Election Day problems as part of a broader effort to encourage them to submit fake electors for certification.

But the Supreme Court majority ruled that a president’s power to direct the Justice Department’s investigative and prosecutorial work is within his exclusive constitutional authority. Trump, the majority ruled, “is therefore absolutely immune from prosecution for the alleged conduct involving his discussions with Justice Department officials.”

When Smith submitted a new indictment this summer, Trump’s alleged interactions with the Justice Department were gone.

Going forward, those interactions are of particular concern for ethics experts. The same would presumably apply to Trump’s oversight of intelligence services and the military, though the high court wasn’t explicit on those points.

“At least for the short term, the problem is the Justice Department,” said Richard Painter, a former White House ethics lawyer for President George W. Bush. “The president has near-complete control.”

That is particularly alarming, Painter said, given Trump’s rhetoric during the campaign. The former president has vowed to “go after” Biden and “the entire Biden crime family.” He has also called on Vice President Kamala Harris to be prosecuted.

Some checks remain

Trump’s supporters brush aside the remarks as campaign hyperbole – an extension of the “lock her up” chants at his 2016 rallies that were meant to intimidate Hillary Clinton but never materialized once he entered office.

Others pointed to institutional checks on a president’s power that were in place during Trump’s first term – and remain today. While the Supreme Court granted former presidents wide immunity, the ruling made no such promises to aides in the White House or Justice Department. That could create a line of defense against a president pushing to the edge of the law.

On the other hand, Trump has made clear that he learned from his first term – when White House aides frequently stepped in to thwart him – and has made clear that, this time around, he will install loyalists instead. And a president has significant pardon powers.

The Supreme Court on Friday is also considering whether to hear arguments in an appeal from former Trump chief of staff Mark Meadows, who wants to move his Georgia federal election subversion case to federal court – where he will raise his own immunity claims. A decision could come as soon as Tuesday.

The Supreme Court’s immunity ruling this year also doesn’t change the way federal prosecutors think about evidence, the law and the types of cases that can actually move forward before a judge. Even the conservative Supreme Court and several lower courts repeatedly blocked Trump, who according to a study last year had the worst win rate at the high court of any modern president.

“There’s no law against the president expressing his opinion about who should or shouldn’t be prosecuted, but the Constitution and ethics rules prohibit prosecutors from selecting people for prosecution based on their political views,” Rod Rosenstein, a veteran attorney who worked in the Justice Department in three presidential administrations, told CNN.

“The department didn’t investigate people unless it was justified by the facts and the law during President Trump’s first term,” he said. “And it probably won’t do so in his second term.”