Murray and other legal scholars say that, absent clear guidance from the Supreme Court, a Trump win could lead to a constitutional crisis in Congress. Democrats would have to choose between confirming a winner many of them believe is ineligible and defying the will of voters who elected him. Their choice could be decisive: As their victory in a House special election in New York last week demonstrated, Democrats have a serious chance of winning a majority in Congress in November, even if Trump recaptures the presidency on the same day. If that happens, they could have the votes to prevent him from taking office.

In interviews, senior House Democrats would not commit to certifying a Trump win, saying they would do so only if the Supreme Court affirms his eligibility. But during oral arguments, liberal and conservative justices alike seemed inclined to dodge the question of his eligibility altogether and throw the decision to Congress.

“That would be a colossal disaster,” Representative Adam Schiff of California told me. “We already had one horrendous January 6. We don’t need another.”