I should stress that I am optimistic about race in America. I grew up in the 1970s and ’80s in Teaneck, N.J., which voluntarily desegregated in the early ’60s. I had a racially diverse and inclusive educational experience through high school. I graduated from the University of Pennsylvania with an engineering degree and then played professional baseball for nine years, including two stints with the Chicago Cubs. I have stood proudly for the national anthem at thousands of baseball games.

I have found that most people of color try, as I do, to find an innocuous explanation when something bad happens to them. It is a terrible feeling to have to assume the worst of people, to accept that much of the world thinks you are less worthy simply because of the color of your skin. It is far more comforting to find another reason, a more “rational” one.

But you cannot ignore the data, the curve on the graph. Racism’s most prevalent form is subtle and stealthy, and it is no less insidious for it. Yes, I can be wrong about whether a particular ambiguous episode is racist. One point does not make a curve, and one curve does not make a point. An “O.K.” sign means nothing on its own. But racism thrives in ambiguity, in shadows. In this form, it is cowardly with double meanings.

Ambiguity can make people of color feel that their sanity hinges on a single verdict. If the Cubs fan was flashing a white nationalist sign, we are in danger; if he was not, we are “politicizing” things or “race-baiting.” This is an incapacitating position to find yourself in, especially when you are just an innocent bystander. You are now forced to redundantly relitigate the existence of racism from a defensive position.

This is why, whether the Cubs fan is innocent or guilty, my life does not just “go on.” I do not have the luxury to decide when I am done talking about racism, because I have to live with it. The public will eventually lose interest in this controversy; the Cubs can return to their bullpen questions. There can be a collective sigh of relief that racism is a topic we don’t have to discuss anymore; we can even declare ourselves “post-racial.”

If the Cubs fan is innocent, he will be O.K. That would be the just outcome. But racism will remain. Being wrongfully accused, while unfair, is not the same as living a life where your skin color automatically makes you a target. Being on guard about hate is not “political.” It is a matter of simple self-protection.

Symbols are the easy part of racism to endure. Racism is not just a symbol or a feeling; it also is a system. It is institutional power that can crush neighborhoods, generations of children, stripping people of validation, self-worth and opportunity. Those who have been subjected to this misuse of power are never certain that they will be O.K.