system
A chat on subreddit /r/PoliticalCompassMemes
human
If by modern we mean "since 1945" which isn't too unreasonable, there are a decent number of presidents gunning for the spot. 

* LBJ sent young men to die in Vietnam (And was probably a sexual predator) 
* Nixon (And Kissenger) probably committed treason (Also Watergate, obviously)
* Jimmy Carter completely failed to respond to an economic crisis
* In addition to (most) things on the chart, Reagan also likely committed treason with Iran-Contra, didn't just ignore Saddam Hussein, he sent him weapons, exploded US spending to "win" the cold war that was really only going one way, and AIDS, and lots of other things too.
* Evidence would suggest Bill Clinton is a pedophile
* George Bush started the war in Iraq for no good reason
* Obama supported the Saudi intervention in Yemen
* Trump tried to overthrow the government
* Word is still out on Biden. I'm expecting his presidency to just fade into mediocrity.

I think Bush Jr, Trump, and Reagan all make the top 3, but honestly ordering them is pretty hard. Personally I think trying to overthrow the US government is probably the worst thing on here, so that would give Trump #1, but you could definitely argue the war in Iraq has been bad enough it should be Bush, or that everything Reagan did was so bad together he should be #1.
gpt
This is a really good take. One thing I think a lot of people miss is that the president has much more power over foreign affairs than domestic.