On a high wall overlooking the central court of the National Museum of African American History and Culture in Washington, D.C., the words of novelist James Baldwin are etched in stone:

“The great force of history comes from the fact that we carry it within us, are unconsciously controlled by it ... History is literally present in all that we do.”

Baldwin’s words are particularly apt this week, as our leaders, for the millionth time, use and abuse race for their own purposes, committing sins against the past and the present.

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Before President Donald Trump entered the fray, the Democrats were engaged in the sort of tussle that couldn’t help but bring a smile to the lips of their opponents.

Nancy Pelosi was attempting to corral her wayward members — the so-called “squad” of Alexandria Ocasio-Cortez, Ayanna Pressley, Rashida Tlaib and Ilhan Omar.

Pelosi, clearly worried that four extremists were becoming the face of the Democratic Party, thus diminishing the likelihood of Democratic success in 2020, had rapped their knuckles in a closed-door session last week.

She warned the newcomers not to tweet against fellow Democrats, and added: “All these people have their public whatever and their Twitter world. But they didn’t have any following. They’re four people and that’s how many votes they got.”

Zing.

In a different era, the smack of the speaker’s ruler would have cowed the upstarts. Speakers could determine what committees members sat on, whether projects were funded in their districts and, indirectly, how much money they could raise.

But in the internet age, parties and leaders have lost influence. Social media allows members to reach their niche audiences and keep the money flowing. The more performative they are on Twitter, the more secure.

And so, the freshmen did what progressives so often do — they reached for the accusation of racism.

Pelosi, they warned, should remember that they are women of color and watch her step.

That’s a sin against history. By carelessly flinging the accusation of racism, they dishonor those millions — so affectingly chronicled in the National Museum of African American History and Culture — who suffered the real thing.

Being disagreed with is not racism, no matter what your college diversity workshop may have taught. This is precisely the kind of overreach that turns off the majority of Americans. It is the fulfillment of the old political prayer: “Oh Lord, let my enemies go too far.”

And then Donald Trump joined the discussion. With a few keystrokes, he transformed an embarrassing moment for Democrats into a disgraceful one for Republicans. By taunting the four Democratic freshmen to go back to their countries (three are native-born), he rescued the Democrats from having to grapple with their overuse of racism accusations. He put them right back into their comfort zone. His tweets (unlike Pelosi’s pointed criticisms) really are racist.

Democrats have often shamed themselves by falsely charging racism.

George W. Bush, for example, who campaigned in black churches, learned Spanish and made No Child Left Behind one of his first priorities, was branded a racist in ads run by the NAACP.

It was a gross injustice.

But just because Democrats have been irresponsible in calling people racists doesn’t mean Republicans get a free pass when the real thing shows up.

Trump, who refers to black nations as “s---hole countries” and pines for Norwegian immigrants; who says a “Mexican” judge (who was born in Indiana) cannot be objective; who thinks there were “good people” on both sides in Charlottesville; who resisted renouncing KKK support; who falsely claimed that Muslims celebrated 9/11 in the NY suburbs; who picks fights with NFL players; and who now leads crowds in cheers of “send her back” about an elected member of Congress, well, you can’t escape history either.

Sen. Lindsey Graham denied that Trump’s comments on Omar were racist. “That’s just the way he is. It’s more narcissism than anything else.” That doesn’t wash. We live with the burden of the past. It demands that we show some decency.

Every Republican who is reflexively defensive of Trump’s blatant nativism and racism should put him or herself in the shoes of immigrants and minorities.

How can they not feel frightened when he is willing to stoke such ugly flames? How can they avoid remembering the Chinese Exclusion Act, the internment of Japanese Americans and, going back to pre-Civil War days, the repeated efforts to deport African Americans through colonization?

That is part of what Trump has dredged up.

It seems that he is out to prove that there is no bottom to what Republicans will accept.

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