Definitely Trump. Tried to subvert democracy, wholly unprofessional attitude as president (in my opinion the first president to not even attempt "rising to the office" at all), handled the economy with the tact of a middle schooler, and (allegedly) divulged / kept classified documents. He is also a civilly liable rapist. All of this I think makes Trump the third worst president of all time, behind James Buchanan and Franklin Pierce.
George Bush is easily the second worst president in modern history, his initial response to 9/11 was a highpoint, but afterwards he started a useless war and, although he incorrectly wouldn't see it this way, bent at the knee to terrorism by subverting constitutional rights for the purposes of mass searches and seizures of information without a warrant or reasonable cause. (i.e. Patriot Act). It's been a while since I hashed out a whole list, but I believe I had Bush somewhere between 7th and 12th worst or so.
Both are absolute pieces of shit.