I absolutely HATE when people think that Atheism is un-American. America is SECULAR. Freedom of religion is one of our basic rights as Americans, so by saying someone's beliefs are un-American, you are saying the First Amendment is un-American.
It started with politicians dividing the people with us versus them. It started with intolerance and hate speech and when people stopped caring they became desensitized mindlessly obedient and turned a blind eye. It also started with GUN CONTROL.