Which president(s) do you think are the root cause for most modern day American problems as a result of that president(s) administration(s)?
Personally, gotta be Woodrow Wilson. Set back race relations more than 50 years as a result of his staunchly pro-segregation sentiment, was borderline authoritarian (sedition and espionage act, strong executive powers) which set up a lot of the extremism we see today, Wilsonianism partially caused WWII to happen and led to increased U.S. foreign intervention (War Hawks), and expanded the federal government’s reach dramatically more than what it was meant to be.