The dossier’s latest blow came last year when the identity of Mr. Steele’s collector was revealed. He turned out to be a Russian-born lawyer, Igor Danchenko, who now lived in the United States. Mr. Danchenko, like others in the private intelligence business, had stumbled into it after other pursuits failed. His contacts within Russia appeared to be not Kremlin A-listers but instead childhood friends, college buddies or drinking pals. In 2017, Mr. Danchenko claimed to the F.B.I. during a secret interview that Mr. Steele had “misstated” the information and had “exaggerated” its reliability. But after that interview was released in 2020, Mr. Danchenko flip-flopped. He told one newspaper that he stood by the dossier; he told another newspaper that he wasn’t so sure about it. By then, a few reporters who had written about the dossier had backed away from it. “Some people have wanted to maintain that the dossier is checking out when, as far as I can tell, it hasn’t,” said Michael Isikoff of Yahoo News. He was in the minority. When Erik Wemple of The Washington Post wrote a series of columns about the media infatuation with the dossier, most journalists he contacted either defended their work or ignored his inquiries.