re: How much evidence do they already have?

At best maybe some intel docs that they are not really worried about. It's not about the documents.

The catalyst was an article by Maggie Hagerman that showed a torn note in a toilet with Stefanik's name on their and the quoting of a source in Trump's inner circle that said this was commonplace.....but this person is the only one saying this.

Presidents destroy handwritten stuff all the time. I have a friend who was Secret Service who told me that Obama and Bush used to throw handwritten notes away regularly