Trump's tweets telling minority congresswomen to “go back” to their countries follows a history of racism and nativism. Voters will decide if this is effective. (Video: The Washington Post)

George T. Conway III is a lawyer in New York.

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.”

Karen Tumulty: We need someone who can lift us up again. Enter President Obama.

Which, in turn, bred another kind of resentment: Why, asked many an unaffluent white parent, who may never have uttered a racial slur or whose ancestors may never have held anyone in bondage, does my child have to check a box to her detriment, or be accused of “white privilege,” when the only privilege she has received came from the sweat of my brow? Why are people like me being called racist, when all I’ve done was mind my own business?

And how naive an adult could be. The birther imaginings about Barack Obama? Just a silly conspiracy theory, latched onto by an attention seeker who has a peculiar penchant for them. The “Mexican” Judge Gonzalo P. Curiel incident? Asinine, inappropriate, a terrible attack on the judiciary by an egocentric man who imagined that the judge didn’t like him. The white supremacists’ march in Charlottesville? The president’s comments were absolutely idiotic, but he couldn’t possibly have been referring to those self-described Nazis as “good people”; in his sloppy, inarticulate way, he was referring to both sides of the debate over Civil War statues, and venting his anger about being criticized.

No, I thought, President Trump was boorish, dim-witted, inarticulate, incoherent, narcissistic and insensitive. He’s a pathetic bully but an equal-opportunity bully — in his uniquely crass and crude manner, he’ll attack anyone he thinks is critical of him. No matter how much I found him ultimately unfit, I still gave him the benefit of the doubt about being a racist. No matter how much I came to dislike him, I didn’t want to think that the president of the United States is a racial bigot.

But Sunday left no doubt. Naivete, resentment and outright racism, roiled in a toxic mix, have given us a racist president. Trump could have used vile slurs, including the vilest of them all, and the intent and effect would have been no less clear. Telling four non-white members of Congress — American citizens all, three natural-born — to “go back” to the “countries” they “originally came from”? That’s racist to the core. It doesn’t matter what these representatives are for or against — and there’s plenty to criticize them for — it’s beyond the bounds of human decency. For anyone, not least a president.

Dana Milbank: The racism stops when Trump goes back to the place from which he came

What’s just as bad, though, is the virtual silence from Republican leaders and officeholders. They’re silent not because they agree with Trump. Surely they know better. They’re silent because, knowing that he’s incorrigible, they have inured themselves to his wild statements; because, knowing that he’s a fool, they don’t really take his words seriously and pretend that others shouldn’t, either; because, knowing how damaging Trump’s words are, the Republicans don’t want to give succor to their political enemies; because, knowing how vindictive, stubborn and obtusely self-destructive Trump is, they fear his wrath.

But none of that is good enough. Trump is not some random, embittered person in a parking lot — he’s the president of the United States. By virtue of his office, he speaks for the country. What’s at stake now is more important than judges or tax cuts or regulations or any policy issue of the day. What’s at stake are the nation’s ideals, its very soul.

Read more:

The Post’s View: Trump’s racist tweets are one of the lowest moments of his presidency

Michael Gerson: Trump never takes a vacation from provocation

Richard Cohen: Republicans must acknowledge that their party has been taken over by a racist

Max Boot: I may not agree with AOC’s squad, but they are better Americans than Trump

Henry Olsen: Yes, Trump’s tweets are offensive. But there’s one big reason Republicans still stand by him.