The FBI and special counsel Robert Mueller
are investigating Trump's 2016 campaign, including whether Trump obstructed justice by firing Comey in May--and it's possible that Comey, McCabe and Baker could be witnesses in that probe. Comey has already testified before the Senate Intelligence Committee, in June, and McCabe met with the House Intelligence Committee on December 19. Both committees are overseeing their own investigations into Russia's election meddling and possible coordination with the Trump campaign. On December 21, McCabe also met with members of the House Committee on Oversight and Government Reform and the House Judiciary Committee.