For nearly three hours Thursday, the Supreme Court weighed whether former presidents are immune from prosecution and what exactly it means if they are.

Their response will determine whether former President Donald Trump can be tried for attempting to subvert the 2020 election.

Whatever the decision, each justice indicated it would shape American democracy for years to come.

“We’re writing a rule for all ages,” said Justice Neil Gorsuch.

The case, heard in a special session a day after the court’s last scheduled argument for this term, revolves around Trump’s claim that he is entitled to absolute immunity from criminal charges for actions committed while in office.

According to Trump, this immunity protects him from criminal charges brought by US Special Counsel Jack Smith for allegedly attempting to overturn the results of the 2020 election.

That trial will remain on hold until the court issues its decision, scheduled for June.

The judges’ direct questions, directed at both sides, indicated division within the court and suggested a split decision was likely. That split could also lead to a more complicated decision that would significantly delay any restart of the trial.

Their questions, along with tense exchanges and high-stakes hypothetical scenarios, also showed that both the conservative majority and the liberal minority are making the decision with an eye toward history. Would full immunity mean that a future president would be free to use the US military to kill his rivals? Or, without it, would presidents who leave office be subject to the whims of individual prosecutors and imprisoned as part of political vendettas?

They also mentioned the pardon of another former president, Richard Nixon, for his role in the Watergate cover-up, and Operation Mongoose of the 1960s, where then-President John F. Kennedy had the Central Intelligence Agency conduct operations covert actions against Fidel Castro.

While the conservative side seemed open to the idea that all former American presidents should have some degree of immunity, all the justices were skeptical of arguments made by Trump’s lawyer, Dean John Sauer, that a former president has almost complete protection against processing.

Answering questions first, the nine judges questioned Mr. Sauer about the breadth of that protection.

“What if the president orders the military to stage a coup?” asked Justice Elena Kagan, one of the court’s three liberal justices.

Sauer seemed hesitant to respond before saying that “it would depend on the circumstances.”

Justice Kagan, sounding incredulous, responded, “That sounds pretty bad, doesn’t it?”

Later, following this same thread, Justice Ketanji Brown Jackson, also a liberal, expressed concern that if past presidents were completely protected from criminal prosecution, they would be free from the law.

“I’m trying to understand what the disincentive is to make the Oval Office the headquarters of crime,” he said.

The conservative justices also pressed Sauer on the distinction between “official acts” – those performed as part of presidential duties – and private acts.

“My question is whether the very strong form of immunity that you advocate is necessary,” asked Samuel Alito, one of the court’s most conservative justices.

But Michael Dreeben, a representative of the US government, faced the same pointed questioning as the judges considered the consequences of leaving US presidents without some level of criminal protection.

What would happen if a president led a violent attack on foreign soil, asked Justice Clarence Thomas. Could that president be subsequently impeached?

Dreeben responded that “layers of protection” already exist to protect presidents from criminal liability for doing their jobs, including actions taken abroad.

Justice Alito, in particular, was concerned about another possible consequence: that presidents could be subject to partisan attacks, perhaps by their successors, once they leave office.

“This could destroy the presidency as we know it,” said Justice Alito, who dominated the second half of the hearing.

But the conservative justices did not present a united front.

Judge Amy Coney Barrett, a Trump appointee, seemed to doubt the notion that presidents deserve blanket immunity.

When Dreeben said there was “no perfect system” for handling a president’s culpability, but that the current system would not be improved by Trump’s “radical proposal,” Judge Barrett responded, “I agree.”

A fractured ruling — one that is not entirely on the side of Trump’s lawyer or the special counsel — could send the issue or part of it to lower courts to decide. This would surely add further delays and be subject to appeal, meaning this legal battle will continue for months, if not years, to come. .