I think there's a few pending court cases, one being The Trump Organisation's alleged real estate fraud. He is alleged to have over valued his holdings to get loans, and then under valued them to get tax concessions.Petulant child
I read an article about the same thing which said he is also upset because if he has the power to pardon himself (which is not clear) it would only be for federal crimes. That means he is not protected from prosecution by the state of New York which is coming after him big time.
I think the litigators are going to come from the woodwork come 21/01/21.