Biden and Trump - What's the Initial Violation?

Biden is saying he's surprised by the existence of these documents at all. They knew about them on November 2nd, so what did they do between then and now that we don't even know about? Why did we just learn about them now? That's why the midterm. But the initial violation is the same. And also, I wonder to what extent, you know, and I'm certainly no apologist for Trump, some of this just has to do with understanding how to use the mechanisms of power in a place like D.C.