WALL STREET JOURNAL: All Mr. Comey’s Wiretaps: Congress needs to learn how the FBI meddled in the 2016 campaign.

When Donald Trump claimed in March that he’d had his “wires tapped” prior to the election, the press and Obama officials dismissed the accusation as a fantasy. We were among the skeptics, but with former director James Comey’s politicized FBI the story is getting more complicated.

CNN reported Monday that the FBI obtained a warrant last year to eavesdrop on Paul Manafort, Mr. Trump’s campaign manager from May to August in 2016. The story claims the FBI first wiretapped Mr. Manafort in 2014 while investigating his work as a lobbyist for Ukraine’s ruling party. That warrant lapsed, but the FBI convinced the court that administers the Foreign Intelligence Surveillance Act (FISA) to issue a second order as part of its probe into Russian meddling in the election.

Guess who has lived in a condo in Trump Tower since 2006? Paul Manafort. . . .

It is thus highly likely that the FBI was listening to the political and election-related conversations of a leading contender for the White House. That’s extraordinary—and worrisome.

Mr. Comey told Congress in late March that he “had no information that supports those [Trump] tweets.” Former Director of National Intelligence James Clapper was even more specific that “there was no such wiretap activity mounted against—the President-elect at the time, or as a candidate, or against his campaign.” He denied that any such FISA order existed. Were they lying?

The warrant’s timing may also shed light on the FBI’s relationship to the infamous “ Steele dossier.” That widely discredited dossier claiming ties between Russians and the Trump campaign was commissioned by left-leaning research firm Fusion GPS and developed by former British spy Christopher Steele—who relied on Russian sources. But the Washington Post and others have reported that Mr. Steele was familiar to the FBI, had reached out to the agency about his work, and had even arranged a deal in 2016 to get paid by the FBI to continue his research.

The FISA court sets a high bar for warrants on U.S. citizens, and presumably even higher for wiretapping a presidential campaign. Did Mr. Comey’s FBI marshal the Steele dossier to persuade the court?

All of this is reason for House and Senate investigators to keep exploring how Mr. Comey’s FBI was investigating both presidential campaigns. Russian meddling is a threat to democracy but so was the FBI if it relied on Russian disinformation to eavesdrop on a presidential campaign.

This stinks.