To this day, I can remember almost the precise spot where it happened: a supermarket parking lot in eastern Massachusetts. It was the mid-1970s; I was not yet a teenager, or barely one. I don’t remember exactly what precipitated the woman’s ire. But I will never forget what she said to my mother, who had come to this country from the Philippines decades before. In these words or something close, the woman said, “Go back to your country.”

I remember the incident well, but it never bothered me all that much. Nor did racial slurs, which, thankfully, were rare. None of it was troublesome, to my mind, because most Americans weren’t like that. The woman in the parking lot was just a boor, an ignoramus, an aberration. America promised equality. Its constitution said so. My schoolbooks said so. The country wasn’t perfect, to be sure. But its ideals were. And every day brought us closer to those ideals.

To a young boy, it seemed like long ago that a descendant of slaves had prophesied, five days before I was born, that his “four little children will one day live in a nation where they will not be judged by the color of their skin but by the content of their character.” We would be there soon enough, if we weren’t there already. I couldn’t understand why colleges required applicants to check boxes for race or ethnicity. I’m also part Irish and Scottish. What box should I check? Should I check one at all? Will that help me or hurt me? Never mind, not to worry, those boxes would someday soon be gone.

How naive a child could be. The woman in the parking lot — there were many more like her, it turned out. They never went away. Today they attend rallies, and they post ugliness on Facebook or Twitter. As for the victims of historic racial oppression, no matter how much affirmative action (or reverse discrimination, or whatever you want to call it) the nation offered, they, too, had resentments that never went away — in part because of people like the parking-lot woman. Those resentments often led to more, not fewer, charges of racism as the years passed — charges of institutional racism and “white privilege.”