It’s no secret that the United States is a house divided in 2017, and that Americans of different political persuasions agree on little when it comes to Washington. But there’s at least one tall exception to this state of affairs, and his name is James B. Comey.

The FBI director was on Capitol Hill Tuesday, testifying to the Senate Intelligence Committee on what the bureau knows about Russian cyber espionage efforts in the 2016 election. Asked whether the FBI is investigating alleged links between the Russian government and...