WASHINGTON — Seven months ago, a respected former British spy named Christopher Steele won a contract to build a file on Donald J. Trump’s ties to Russia. Last week, the explosive details — unsubstantiated accounts of frolics with prostitutes, real estate deals that were intended as bribes and coordination with Russian intelligence of the hacking of Democrats — were summarized for Mr. Trump in an appendix to a top-secret intelligence report.
The consequences have been incalculable and will play out long past Inauguration Day. Word of the summary, which was also given to President Obama and congressional leaders, leaked to CNN Tuesday, and the rest of the media followed with sensational reports.
Mr. Trump denounced the unproven claims Wednesday as a fabrication, a Nazi-style smear concocted by “sick people.” It has further undermined his relationship with the intelligence agencies and cast a shadow over the new administration.
Late Wednesday night, after speaking with Mr. Trump, James R. Clapper Jr., the director of national intelligence, issued a statement decrying leaks about the matter and saying of Mr. Steele’s dossier that the intelligence agencies have “not made any judgment that the information in this document is reliable.” Mr. Clapper suggested that intelligence officials had nonetheless shared it to give policymakers “the fullest possible picture of any matters that might affect national security.”
Fusion GPS, headed by a former Wall Street Journal journalist known for his dogged reporting, Glenn Simpson, most often works for business clients. But in presidential elections, the firm is sometimes hired by candidates, party organizations or donors to do political “oppo” work — shorthand for opposition research — on the side.
It is routine work and ordinarily involves creating a big, searchable database of public information: past news reports, documents from lawsuits and other relevant data. For months, Fusion GPS gathered the documents and put together the files from Mr. Trump’s past in business and entertainment, a rich target.