But by discussing when “a document is used to go to court,” Graham seemed to refer to the dossier and the FISA court. And he seemed to suggest that, if the FBI used revelations from the dossier to secure a warrant to spy on Americans, it was not fully transparent about the source of those revelations, which was an opposition-research project funded by the Hillary Clinton campaign. FBI and Justice Department officials have told Congress they have not been able to verify the dossier’s substantive allegations of collusion between Russia and the Trump campaign.

Further, Graham found the dossier affair serious enough to warrant an entirely new investigation. It’s not in Mueller’s charter, Graham said. And Graham does not appear to trust the Justice Department to investigate itself on this particular issue.