President Joe Biden said he “can’t think of one” reason presidents should receive absolute immunity from prosecution, as Republican front-runner Donald Trump has claimed.

Biden made the comment in response to a reporter’s question Saturday before departing the White House for Camp David, where he will spend Christmas. The Supreme Court on Friday declined to fast-track a decision on Trump’s immunity case.

The justices’ decision hampered federal prosecutors’ efforts to start Trump’s trial on charges related to his attempts to overturn the 2020 election. The former president argues he was acting within his official duties during the lead-up to the Jan. 6, 2021 riot, in which his supporters violently stormed the U.S. Capitol in an attempt to prevent lawmakers from certifying Biden’s victory.

The trial is scheduled to begin March 4 and Special Counsel Jack Smith sought to speed the matter to the nation’s highest court in order to ensure the start date. Now, a lower federal appeals court will consider the immunity claim, meaning the trial could spill into the heart of the general election or later.

Biden’s campaign is planning to frame the contest, which will likely feature a Trump rematch, as a repeat of the 2020 election but with even bigger stakes. His campaign circulated a memo last week casting Trump as a mortal threat to U.S. democracy, citing Trump’s conduct ahead of Jan. 6 and his threats to exact retribution on his political opponents.

Biden said Wednesday that Trump “certainly supported an insurrection” on Jan. 6, though he declined to endorse a Colorado Supreme Court decision that would bar the former president from the ballot in the state. “That’s up to the court,” Biden said.