The legal consequences of President-elect Donald J. Trump’s victory start with the likelihood that the cases against him will sputter out but could also extend to the cases of hundreds of his supporters who are being — or have been — prosecuted for storming the Capitol on Jan. 6, 2021.

On the campaign trail, Mr. Trump repeatedly promised to pardon some of the 1,500 people charged in connection with Jan. 6, sometimes suggesting that his clemency might extend to leaders of far-right groups like the Proud Boys and to other defendants who assaulted police officers.

It remains unclear whether or how fully he will fulfill those vows. But should he issue wide-ranging pardons, it would amount to a repudiation of the largest criminal investigation ever undertaken by the Justice Department and damage, perhaps fatally, efforts by prosecutors to seek accountability for a violent mob attack on the lawful transfer of presidential power.

Already, some Jan. 6 defendants are excitedly expressing hope that Mr. Trump might strip them of convictions or free them from prison when he takes office.

Only hours after the election was called for Mr. Trump early Wednesday, one convicted rioter, Christopher Carnell, asked a federal judge to push back a hearing in his case, saying he “expected” to receive clemency.

“Throughout his campaign, President-elect Trump made multiple clemency promises to the Jan. 6 defendants, particularly to those who were nonviolent participants,” Mr. Carnell’s lawyers wrote. “Mr. Carnell, who was an 18-year-old nonviolent entrant into the Capitol on Jan. 6, is expecting to be relieved of the criminal prosecution that he is currently facing when the new administration takes office.”