The white marble steps of the Lincoln Memorial are a sacred place for America.

And they're about to get stained.

It's the place of reckoning for our great nation's original sin - the practice of slavery and the segregation and racism that still rock this country today. And it's a place that honors sacrifice and the earth-moving impact of eloquence on American history.

Now a showman with no appreciation for that history is going to squat on that spot this July Fourth.

President Donald Trump's takeover of Washington's Fourth of July celebration isn't just a logistical nightmare that's disrespectful to the city, the nation and the holiday. His insistence on speaking at the Lincoln Memorial - and undoubtedly delivering the narcissistic ramblings that are the hallmark of his appearances - is an affront to President Abraham Lincoln's spare brilliance, the Rev. Martin Luther King Jr.'s thundering oratory and Marian Anderson's unforgettable contralto.

Let's start with how unworthy Trump is to share space with the legend of Lincoln, the man who emancipated enslaved Americans, saved the Union and gave his life in the process.

"Though he loved Caesar less than Rome, though the Union was more to him than our freedom or our future, under his wise and beneficent rule we saw ourselves gradually lifted from the depths of slavery to the heights of liberty and manhood," said Frederick Douglass at the April 4, 1876, dedication of the smaller Lincoln memorial on Capitol Hill, in Lincoln Park.

Douglass, who met with Lincoln at the White House in 1863, didn't spare examining Lincoln's complicated relationship with slavery and race in his speech, but he was prescient about the impact Lincoln would have on generations of Americans.

Lincoln encouraged us, he said, "to build high his monuments; let them be of the most costly material, of the most cunning workmanship; let their forms be symmetrical, beautiful, and perfect, let their bases be upon solid rocks."

And it was at the symmetrical, costly and grand memorial eventually built that one of the most elegant acts of American protest took place.

It was 1939, and Anderson, an American singer beloved abroad, was invited to perform in Washington. She was so big in Europe, organizers needed a huge space to hold all her fans. And Constitution Hall, run by the Daughters of the American Revolution, was perfect.

But the Daughters had a white-only clause in their contract and wouldn't let Anderson perform.

First lady Eleanor Roosevelt, a member of the DAR, was outraged by their action, resigned and asked Washington officials to find an appropriately grand and commodious place for Anderson to perform.

Folks from the NAACP had an idea. How about outdoors?

So instead of the singing to just 3,000 or so people in that racist hall, Anderson sang for 75,000 people from the steps of the Lincoln Memorial on April 9, 1939. On Easter Sunday.

She began with "My Country, 'Tis of Thee." It was more than a performance. It was a repudiation of racism.

Almost 25 years later, on Aug. 28, 1963, King spoke to more than 200,000 people who participated in the March on Washington. They heard him deliver one of the most famous speeches in American history.

On those steps, which today mark the exact spot where he stood, King said he had "a dream that one day this nation will rise up and live out the true meaning of its creed: 'We hold these truths to be self-evident, that all men are created equal.' "

There's personal history on those steps, too - hundreds of thousands of confessions, marriage proposals, revelations and reflections.

Trump won't be the first president to misuse the memorial. Richard Nixon beat him to it.

On the morning of May 9, 1970, days after President Nixon announced that U.S. troops would move into Cambodia and four students were shot and killed at Kent State University during a Vietnam War protest, a huge antiwar crowd began to gather outside the Lincoln Memorial.

At 4 a.m., Nixon insisted on going to the memorial to address the demonstrators.

"I said I was sorry they had missed it because I had tried to explain in the press conference that my goals in Vietnam were the same as theirs - to stop the killing, to end the war, to bring peace," Nixon later said, in his disputed account of the event. "I hoped that their hatred of the war, which I could well understand, would not turn into a bitter hatred of our whole system, our country, and everything that it stood for. I said: 'I know you, that probably most of you, think I'm an SOB. But I want you to know that I understand just how you feel.' "

The protesters weren't buying it. But that isn't the worst stain left at this sacred place.

When the memorial was dedicated on May 30, 1922, the audience of 50,000 was segregated.

Yes, the tribute to the great emancipator was segregated.

Now Trump will leave his mark on the Lincoln Memorial. And that stain - like his presidency - won't ever completely wash away.

Petula Dvorak is a columnist for The Washington Post's local team.