He’s been shown to indirectly threaten judges, juror, investigators, and witnesses. By turning the hate and violence of his supporters their way. He doesn’t have to personally do anything, there will always be a sympathizer willing to lay down their own life and well-being for his political cause, that’s how fascism works.
He very much can retaliate. And has a rich history of it at this point.
Another way that retaliations can be had is with a corrupt Supreme Court who are influenced by external parties by way of wealth or influence. In which case sources of wealth can be pulled or affected.
Good thing we don’t have any Supreme Court members on dubious grounds related to ill-gotten gains…