A three-judge panel of the federal appeals court in Washington heard arguments on Tuesday in a momentous case over former President Donald J. Trump’s claim that he is immune from criminal charges for the efforts he took to overturn the 2020 election.

A ruling by the court — and when it issues that decision — could be a major factor in determining when, or even whether, Mr. Trump will go to trial in the federal election case.

Here are some takeaways:

The judges on the Court of Appeals for the District of Columbia Circuit appeared unlikely to dismiss the charges against Mr. Trump on grounds of presidential immunity, as he has asked them to do. The two Democratic appointees on the court, Judge J. Michelle Childs and Judge Florence Y. Pan, peppered John Sauer, a lawyer for Mr. Trump, with difficult questions.

Judge Karen L. Henderson, the panel’s sole Republican appointee, seemed to reject a central part of Mr. Trump’s argument: that his efforts to overturn his loss to President Biden cannot be subject to prosecution because presidents have a constitutional duty to ensure that election laws are upheld.