To deny that human beings are filled with anti-social passions betrays a denial of reality and a lack of self-awareness. One has to be taught nonsense for a great many formative years to believe it.
Leftists' meanness toward those with whom they differ has no echo on the normative right.
Since neither black animosity nor the Left's falsehood of 'racial tensions' is based on the actual behavior of the vast majority of white Americans, nothing white America could do will affect either many blacks' perceptions or the leftist libel.
For the Left, tolerance does not mean tolerance. It means first, acceptance. And second, celebration. That is totalitarianism: You not only have to live with what you may differ with, dear citizen, you have to celebrate it or pay a steep price.