If we assume a Federal warrant there is one set of problems, but a state criminal warrant creates another set of problems, which is why ruling that a sitting President could be sued [Clinton] made everything a mess. The Supreme Court made the ruling, so it must be so.

Trump could be convicted of a crime, but who would actually incarcerate him? The Bureau of Prisons of whom Trump is the head? What would prevent Trump from ordering his own release? Basically, if you convict Trump but he’s not impeached, it has basically no effect. He can simply defy the court’s sentence by ordering his own release from prison, and while the court might try to impose contempt of court, who will enforce that? A U.S. Marshalls Service that is in the Department of Justice, i.e., the executive department, even though it’s the courts that usually order it around? What’s keeping Trump from simply ordering them to stand down while ordering the Secret Service to not let them arrest him?

Talk about your Constitutional crisis!