The news also stunned some of those who had been investigating the matter. Yes, they knew that knowledge of the dossier extended to some officials in the FBI. That was bad enough; how could the FBI endorse and consider underwriting one campaign’s dirt-digging operation in the middle of a hotly contested election? But now investigators know that nearly the highest levels of the Obama Justice Department were also aware of the dossier.

Investigators believe the dossier’s sensational allegations of collusion between Russia and the Trump campaign played a role in the beginning of the FBI’s counterintelligence investigation into the Trump-Russia affair — an investigation that later morphed into special counsel Robert Mueller’s probe.