Ms. Jones, the film colleague, said that in their years working together, Mr. Bannon occasionally talked about the genetic superiority of some people and once mused about the desirability of limiting the vote to property owners.

“I said, ‘That would exclude a lot of African-Americans,’” Ms. Jones recalled. “He said, ‘Maybe that’s not such a bad thing.’ I said, ‘But what about Wendy?’” referring to Mr. Bannon’s executive assistant. “He said, ‘She’s different. She’s family.’”

Mr. Bannon’s African-American friend from his Goldman years said that he had been at pains to defend him in recent years to mutual acquaintances put off first by Breitbart’s reputation and now by Mr. Bannon’s association with Mr. Trump. Most Christmas seasons over the past two decades, he said, Mr. Bannon was “my only token white guy,” or one of two or three, invited to an annual dinner at a New York City club for nearly a score of African-American friends who work or worked in finance.

“Now I’m getting a lot of, ‘What happened to Steve?’” from concerned black acquaintances, the friend said. He said he hoped Mr. Bannon — and more important, Mr. Trump — would more forthrightly denounce the bigots who have cheered them on. Still, he said, he completely rejects the accusations against Mr. Bannon.

“Hell, no, he’s not a white nationalist,” the friend said.