What's stopping trump from selling more pardons after he leaves office,

[StarfishSaver]

36. A few things

Yes. The pardon would have to be verifiable. I don't know if a witness verifying an oral pardon would be sufficient under these circumstances, given the lack of credibility of just about anyone who would be close enough to him to witness it. That would be too much of a chance for him to take, especially since it would be too late to go back and do it right. He would no doubt put it in writing, just to be sure. And most likely he'd submit it to the Justice Department, but just not release the name to the public.

He could try a blanket pardon of the trespassers, but that would be very problematic. The example you gave, for instance, would probably be a valid pardon since, while it doesn't clearly identify all of the persons pardoned, It does pardon them for a specific crime which probably would satisfy any specificity or particularity requirements of court would impose. It's very similar to the amnesty granted to the Vietnam War draft evaders.

But the problem is, by pardoning them for one specific crime, he still leaves them open to prosecution for any number of other crimes they committed i
at the Capitol that day. It doesn't do any good to get pardon for trespassing if you're still wide open to being prosecuted for assault, breaking and entering, illegal presence on federal property, insurrection, sedition, etc. Prosecutors would have a field day coming up with that weren't included in the pardon to nail these people on.

He could try to go broader, but I don't think that would work either. If he tried to pardon everyone who was there for every possible crime they could have committed at the Capitol that day, not only would that leave too many people out (what about the people who helped plan and carry it out, but weren't physically on site?) and too broadly include too many people (a Hill staffer not involved in the riot but who embezzled $100k from the office account that day), I don't think a court would find that to be a pardon at all since it's far too broad and unspecific.