Supreme Court Justice Sonia Sotomayor identified a key contradiction underlying former President Donald Trump’s defense at Thursday’s Supreme Court hearing on whether he is immune from prosecution in a case charging him with plotting to overturn the results of the 2020 presidential election.

The discrepancy lies in Trump’s legal team arguing that presidents can’t be prosecuted for “official acts” committed while in office unless they are both impeached and convicted by the U.S. Congress.

For example, even if a president ordered a military coup or sold nuclear secrets to a foreign power — two hypotheticals posed by Supreme Court Justice Elena Kagan during the hearing — Trump couldn’t be held criminally liable without an act of Congress, his attorney, John Sauer, argued.

Furthermore, Trump’s legal team said that there needs to be a “clear statement” in the statute covering such acts that directly apply to the president. Otherwise, their liability would be moot.

But the liberal justices on the court, including Sotomayor and Ketanji Brown Jackson, pushed back against that line of reasoning aggressively. They noted that it essentially created a Catch-22 by preventing a president from being impeached at all.

“If we say a president can’t be included in a criminal law unless explicitly named, then that would bar the Senate from convicting him for high crimes or misdemeanors because that means that he’s not subject to the law at all,” Sotomayor said.

“If he’s not covered by the criminal law, he can’t be impeached for violating it at all,” she added.

Jackson also said the legal team’s argument “seems completely tautological to me.”

“For us to hold that presidents cannot be prosecuted under any criminal statute without a clear statement from Congress to avoid the question of whether or not the Constitution allows them to be prosecuted, we’d have to have a reason,” she said.

Impeachment doesn’t necessarily require criminal behavior to take place, but Trump’s legal team argued during his January 2020 impeachment trial that only a charged crime can be grounds for impeachment.

The 6-3 conservative majority on the high court, meanwhile, seemed poised to sidestep having to rule on Trump’s claims for absolute immunity by remanding the case to a lower appeals court for additional hearings. They suggested that the court needed more information to determine what is or isn’t an “official act” carried out by a president. Trump’s team has said that his actions in seeking to submit alternate slates of electors were official acts.

“What concerns me is the court of appeals did not get into focused consideration about what acts we’re talking about,” Supreme Court Justice John Roberts said.

A further delay in the proceeding would likely mean that the Department of Justice case against Trump for his unprecedented efforts to overturn an election he lost won’t be heard in court until after the November 2024 presidential election, if at all.

Democrats reacted to the hearing on Thursday with dismay, slamming the Supreme Court for dragging their feet.

“He’s obviously not immune,” Senate Majority Leader Chuck Schumer (D-N.Y.) wrote in a post on X, formerly Twitter. “SCOTUS is only protecting Trump and slowing his trial. SCOTUS should not have taken this case or frozen the district court. SCOTUS speeds up trials when it wants—but not in this case.”