A photo of a young white woman screaming in an NYPD officer’s face makes me wonder what he’d do if I did that. I think I’d better not.In recent months, thousands of people from all walks of life have flooded the streets of our cities. No matter what you believe about these protests, there is beauty in watching diverse groups of people—black and white, alike—come together in the name of racial equality. Yes, some people have been inconvenienced by traffic delays or annoyed by supportive athletes. But even they should see the marches as expressions of our best and highest...