As The Times’s Joseph Goldstein reported on Monday, members of the movement held 11 hours of speeches and panel discussions. The conference culminated Saturday evening in a speech by the movement’s leading ideologue, Richard Spencer, who accused the news media of attacking Mr. Trump during the campaign to protect Jewish interests. Speaking of political commentators, he said, “One wonders if these people are people at all, or instead soulless golem” — creatures of fable that were set in motion by rabbis in time of danger.

Mr. Spencer quoted Nazi propaganda — in German — and reinforced his often-stated view that America belonged to white people: “America was, until this last generation, a white country designed for ourselves and our posterity. It is our creation, it is our inheritance, and it belongs to us.”

This speech echoed remarks Mr. Spencer made earlier last week in an interview with NPR, when he said that his goal was to make the United States a “big empire that would accept all Europeans” and be a “safe space” for white Americans, Slavs, Celts and so on.

He went on in that interview to say that legal immigration — the lifeblood of the United States — was the most damaging kind, apparently because the country does not have a racial test that favors whites. He declined to condemn the Ku Klux Klan, a group that promotes racial terror, because people wearing white robes are merely “expressing themselves” or getting in touch with their “identity as a European.”

The young, suit-and-tie white supremacists who traveled to Washington had no idea a year ago that their views would be getting a hearing in mainstream political discourse, much less finding sympathy in the White House. But Mr. Trump ensured that outcome by playing to white nationalism during the primaries, then choosing as his campaign chairman Mr. Bannon, who managed the alt-right’s most visible platform.