In the 2016 general election debates, Mr. Trump repeatedly complained about being at a disadvantage to Hillary Clinton, the Democratic nominee. And the post-debate polls showed Mr. Trump had good reason to be concerned: Mr. Trump and Ms. Clinton were essentially tied in the polls going into the first debate, but she received a bump after each of the three face-to-face matchups.

A Gallup poll conducted after the third debate, for instance, found that 60 percent of viewers thought Ms. Clinton did a better job, while 31 percent chose Mr. Trump.

After his performance in one of the debates was panned, Mr. Trump blamed a “defective mic” and questioned whether it was done “on purpose” to put him at a disadvantage. It turned out that a technical malfunction had indeed affected the volume of his voice during that debate, in September 2016.

That acknowledgment by the commission, however, never mollified Mr. Trump.

His 2016 debate team — led primarily at that time by Rudolph W. Giuliani, the former New York City mayor — also clashed with the commission over where to seat a group of women who had accused former President Bill Clinton of sexual assault or sexual harassment.

The Trump campaign invited the women as surprise guests to the second debate in St. Louis. Mr. Trump wanted them seated in his V.I.P. box, where Mr. Clinton would have to walk past them; they would also have been in her line of sight from the stage. In the end, the campaign had to stand down after the commission threatened to call security and have the women removed.