“If the mob were involved.......it wouldn’t have been so messy and no one would know - ever.”
You know this because of all the famous murders of high officials the mafia’s committed that no one knows about?
American mafiosos don’t go after power. It’s as simple as that. Michael may have killed that police captain in The Godfather, but the president? Ridiculous risk for absolutely no guaranteed benefit. Utterly fanciful.