Steph Solis

USA TODAY

For white nationalists in Washington, D.C., there was cause to celebrate Saturday.

The 200 attendees at the National Policy Institute's annual conference at the Ronald Reagan building celebrated the rise of Donald Trump as president-elect and promoted a conquer-or-be-conquered mentality.

"America was, until this past generation, a white country, designed for ourselves and our posterity," Richard Spencer, a prominent white nationalist within the alt-right movement. "It is our creation. It is our inheritance and it belongs to us."

A video published by The Atlantic, which is working on a documentary on Spencer, shows clips of Spencer's speech for the National Policy Institute, an independent research organization "dedicated to the heritage, identity and future of people of European descent in the United States," according to its website. The Atlantic reported that Spencer envisions “a new society, an ethno-state that would be a gathering point for all Europeans,” and supports “peaceful ethnic cleansing.”

Members of the D.C. Antifascist Coalition protested the conference and an anti-Semitic dinner hosted at Maggiano's on Saturday. Some held banners and posters outside of the Italian restaurant, while at least one protester was seen outside of Trump International Hotel.

Restaurant apologizes for 'inadvertently' hosting alt-right event

Toward the beginning of his speech, Spencer said, "Hail Trump. Hail our people. Hail victory!" and the room broke out in applause. Some raised a hand in a Nazi salute.

Spencer also slammed the press, calling members "genuinely stupid" and promoted a philosophy of "conquer or die" among attendees. "To be white is to be a striver, a crusader, an explorer and a conqueror."

The United States Holocaust Memorial Museum said in a statement it was alarmed at the conference's rhetoric: "The Holocaust did not begin with killing; it began with words. The Museum calls on all American citizens, our religious and civic leaders, and the leadership of all branches of the government to confront racist thinking and divisive hateful speech."

Trump has denounced the racism perpetuated by the alt-right movement, CNN reported.