I don’t think you’re right about that. First of all, I’m not sure that releasing classified documents, let alone simply keeping them in your private possession, is actually illegal. Daniel Ellsberg released large numbers of classified documents, and the courts ruled he had done nothing illegal. I think the punishment for releasing them is you get fired, not jailed. you break government policy when you release classified documents, not laws.

That issue is moot, however, because Trump is guilty of other things which Biden is not guilty of. Trump refused to handover the documents once they were subpoenaed. he also lied by saying he had handed all of them over when he hadn’t. Both of these count as obstruction of justice, which is an actual crime.

There is also a question of intention, which changes the culpability of the action. When you discover that you have 20 or pages that you didn’t realize you had, and then immediately report them and hand them over, there was obviously no intention to break either policy or law. it’s a very different matter when you have over 11,000 pages in your possession, then refuse to have them over, and then deny that you have them.