"Being able to definitively tie the Clinton campaign and the D.N.C. to the Steele dossier is sure to give Republicans another line of attack against special counsel
Robert Mueller. But that doesn’t change the fact that much of what Steele found—muddled as it may be by rumor, innuendo, and
possible Russian disinformation—was deemed sufficiently credible by the F.B.I. for the agency to begin working with Steele and, ultimately, to fund his research—at least until his name was made public.
The broader intelligence community found the allegations sufficiently credible that they gave classified briefings to members of Congress and, in January, days before the inauguration, presented a two-page synopsis to then-President Obama and President-elect Trump. Many of those details have since been confirmed, though the dossier’s most outrageous claims have not.
The overall legitimacy of that intelligence, including allegations that Russia may have compromising personal and financial information about the current president, remains a matter of significant public concern."
https://www.vanityfair.com/news/2017/10/hillary-clinton-donald-trump-dossier