There is no crime that cannot be hidden within Us versus Them.
It is a fog which makes clear vision impossible.
And to be clear, it is an aspect of human emotion and instinct, a natural pitfall, but it is rare that both sides are equally guilty.
Political and philosophical Liberalism were created specifically to help build, support and defend a middle. American has historically been a sensible nation governed by middles. The present extremism is an unwanted European import, and perhaps 80-100 years too late.
It is for that specific reason that true Liberals are under attack by those who WANT the fog of division to help conceal past, present and planned future crimes.
At the present, the sides, broadly speaking, are those who view broadmindedness as a virtue, and those who do not.