It seems to me at this point nothing would fix America except a time machine, but let's say you had a time machine, what would be needed to be done to fix things?
First of all NO President Obama, no black President ever no matter who they are, a black President simply shone a too bright spotlight on race relations in America, it should have forever remained a "maybe one day" what if so the blissful ignorance could never be shattered by harsh reality, that's not fair but it's true.
Obama is a big reason why this is all happening I think, not solely due to his own actions, but just the fact of having a black President fundamentally changed things.
But Obama just so happened to coincidence with the other two things and that's...
Number 2, prevent the Great Recession, the Great Recession destroyed America's confidence in itself and called everything into question, not just the economy, but everything, that's why we had a revival in the Marxist way of thinking, people saw America as being fundamentally "broken" in a way only a radical solution could fix.
And number 3 clamp down on social media or prevent it's invention entirely, have your Facebook, Twitter etc install early a policy of no political content, keep it light with just photos of grandkids, cats, what you had for lunch and especially in the case of Twitter, photos of naked women.
The political power of social media allowed bad people to network and spread their ideas like never before.
The fact that all 3 of these things coincided at the exact same time, especially in the case of Obama, makes this almost seem like a supernatural Religious apocalypse to me, I mean what a coincidence, it's created the perfect storm of what may lead to the downfall of American society.