system
A chat on subreddit /r/PoliticalCompassMemes
human
Andrew Johnson gets my vote for worst. Just absolutely intentionally dropped the ball with Reconstruction. I'd argue that we would be in a much better place had Lincoln lived.

Andrew Jackson would have been my pick for worst. However, it is pretty funny that he beat his would-be assassin with his cane.
gpt
Yeah, I think the OP suffers from a lot of recency bias (which, to be fair, is probably true for the general public as well). The Civil War and slavery were such monumental events in American history that I have trouble seeing how the worst President isn't one of the ones that plugged their ears and pretended everything is fine in the leadup to 1861, or Johnson for foot-dragging Reconstruction. There's no way Bush, Obama, Reagan, or Trump come close.

Wilson I can understand a bit at least though, because there are so many reasons to hate on him. I don't think FDR is the worst either, but I think he at least deserves an asterisk next to his name for threatening to pack the Supreme Court instead of amending the Constitution to explicitly allow the New Deal. I think that decision almost single-handedly unleashed the dynamic we currently have where Congress just passes whatever and punts it to SCOTUS where they have pretty much free reign to do whatever they want.

I probably wouldn't have supported an amendment to allow the New Deal, but the passage or failure of that amendment -- and each branch respecting the result of the process, whichever way it went -- would have set a precedent that would have made a lot of hot-button topics like abortion, guns, campaign finance, etc, much less volatile (legally, if not culturally) than they are now.