The door to the apartment in Alexandria opened, and there he was: Richard Spencer, a white nationalist leader in the ultraconservative “alt-right” (read, “make America white again”) movement. On the cusp of Donald Trump’s presidential inauguration, Spencer, a Trump supporter, was setting up shop to promote his cause in the D.C. area.

“Hail Trump,” Spencer and his minions had chanted at a convention in Washington after Trump’s election in November. Spencer has said that he is neither racist nor a white supremacist but an “identarian” who advocates for stronger white identity.

[Inside the alt-right world of Richard Spencer]

When Spencer saw who was at the door on Monday evening, he closed it without saying a word. But his presence had been confirmed.

“The ethno-nationalism, racism, anti-Semitism, excluding people that are not like them, separating and denigrating others — it’s anathema not only to our community but to our society,” said Dennis Maloney said, a consultant in Alexandria who accompanied me to Spencer’s apartment.

I had met with Maloney and two other Alexandria residents — business owner Dylan Raycroft and lawyer Jessica Killeen — to hear them discuss ways to protest Spencer’s mission. The stated goals of some “alt-right” factions include “nonviolent ethnic cleansing” and restoration of “white culture” in a whites-only homeland.

“I’ve never been a political activist, just a businessman trying to be a part of the community the way normal people do,” said Raycroft, who owns a chimney sweep company in Alexandria. But he said the presence of Spencer in the neighborhood “crosses a line that can’t be ignored. There comes a point when you just have to say, ‘Enough is enough.’ ”

In the aftermath of a presidential campaign seared by Trump’s incendiary rhetoric, the Alexandria City Council issued a statement declaring the city a “hate-free zone.” Then Spencer arrived, as if to mock the council’s stated ideals.

For years, there has been a battle for the soul of the city. While one group seeks to make it a more progressive place, another clings fervently to its Confederate past. A recent clash over what to do about a Confederate statue and a street named for the Confederate president, Jefferson Davis, ended in something of a compromise: The statue will stay for now; the name of the highway will be changed.

[Alexandria’s Confederate symbols will stay put for now]

But the arrival of Spencer has tipped the scales. And no amount of political dealing will right it.

Raycroft had read about Spencer’s move to the city in a January issue of the Atlantic. The article did not mention the address. So he used an online real estate service to look up interior photographs of recently rented apartments and match them with photographs that Spencer had tweeted of himself inside his new residence.

“I think the first step is to bear witness,” Maloney said. “Maybe it’s a simple matter of getting people to stand outside that building with signs saying: ‘We are not tolerating this. You are not welcomed.’ There is no reason why we can’t exercise our freedom of speech. That might invite them to engage.”

Killeen was optimistic about getting people involved.

“The election of Trump has caused a lot of people to become politically active for the first time,” she said. “People have been aware of what was going on, but this is the first time they are putting boots on the ground and fighting for things we really care about.”

As word of the new neighbor spread, fliers and posters began cropping up around South Patrick and King Streets. One read: “No Vacancy for Hate” with the hashtag, #inclusivealx. Another read “Missing Dog” and included a photo of Spencer.

The most they could do was use Spencer as a symbol of what the country was at risk of becoming.

“We can’t let people like him become the norm,” Killeen said.

Raycroft shook his head in disbelief.

To read previous columns, go to washingtonpost.com/milloy.