Which leads us to Mr. Comey’s most recent and obvious conflict of all—likely a primary reason he was fired: the leaks investigation (or rather non-investigation). So far the only crime that has come to light from this Russia probe is the rampant and felonious leaking of classified information to the press. Mr. Trump and the GOP rightly see this as a major risk to national security. While the National Security Agency has been cooperating with the House Intelligence Committee and allowing lawmakers to review documents that might show the source of the leaks, Mr. Comey’s FBI has resolutely refused to do the same.

Why? The press reports that the FBI obtained a secret court order last summer to monitor Carter Page. It’s still unclear exactly under what circumstances the government was listening in on former Trump adviser Mike Flynn and the Russian ambassador, but the FBI was likely involved there, too. Meaning Mr. Comey’s agency is a prime possible source of the leaks.
In last week’s Senate hearing, Chairman Chuck Grassley pointed out the obvious: The entire top leadership of the FBI is suspect. “So how,” Mr. Grassley asked, “can the Justice Department guarantee the integrity of the investigations without designating an agency, other than the FBI, to gather the facts and eliminate senior FBI officials as suspects?” Mr. Comey didn’t provide much of an answer.

All this—the Russia probe, the unmasking, the leaks, the fraught question of whether the government was inappropriately monitoring campaigns, the allegations of interference in a presidential campaign—is wrapped together, with Mr. Comey at the center.