The Supreme Court will hear arguments on whether or not Donald J. Trump's name can be legally omitted from the upcoming presidential election ballots on the grounds that, under the 14th Amendment, as an officer of the United States, and having taken an oath to support the Constitution, he violated that oath by engaging in insurrection.
It's pretty obvious that Trump engaged in insurrection. Many judges and legal scholars agree.
But Trump's lawyers seek to get their client off on a technicality. They argue that the POTUS is not an officer of the United States. (Nevermind that a US president takes an oath of office at the beginning of his/her term, that he/she holds office for a term of 4 years, and that the Oval Office is property of the United States government.)
Is the president an officer of the United States under Section 3 of the 14th Amendment? Deceased Supreme Court Justice Antonin Scalia appears to have thought so, as did founding father Alexander Hamilton. See the article in the link below for a full explanation.