Supposedly Pete Rozelle gave a directive that Trump would never be allowed to own an NFL team.
That may eclipse creating the Super Bowl in listing his contributions to the sport.
I don't know that he would have had to do that; as Rozelle pointed out multiple times both before and at the trial, it requires approval by 3/4 of the current ownership, meaning seven "no" votes would shoot you down in 1986. Trump kept telling the lie that Rozelle had wanted him to have a franchise, and Rozelle kept pointing out that even if he had said that (which he strongly denied), he didn't have the power to do it anyway, it would be up to the other 27 owners.
But I do recall reading somewhere that Rozelle said that as long as he or his family members were associated with the NFL, Trump would never be in the league - and he allegedly even pointed his fist into Trump's chest, knowing what an egomaniac the guy is.
28 owners in 1986, meaning 8 could keep him out
Leon Hess - NY Jets
Mara family - NY Giants
Robert Irsay - Colts (Trump had been saying he could have bought the Colts any time he wanted)
Jack Kent Cooke - Washington - Rozelle's wife had been married to Cooke's son first
Edward De Bartolo Jr - San Fran - his dad was a USFL owner, so it's firsthand "no, son, don't"
That's five I'd be willing to bet right now wouldn't have approved, and I can't imagine the Rooney family (Steelers), Art Modell (Browns/Ravens), Lamar Hunt (Chiefs), Bud Adams (Houston, who knew the co-owner, Argovitz, from the Generals), Ralph Wilson (Bills), the Halas/McCaskeys (Bears), or the Sullivan family (Patriots before Kraft) would have voted in his favor.
I honestly think it would have been a 26-1 vote against Trump - with Al Davis dissenting and then whining about what a great thing it would be to have Trump as an owner but this big conspiracy was keeping it from happening.