‘I think spying did occur,” Attorney General William P. Barr told a Senate subcommittee last Wednesday. He was speaking about the Federal Bureau of Investigation’s probe into possible coordination between Russia and the Trump campaign, as well as the resulting special-counsel investigation.

I can tell Mr. Barr what I know from experience. There’s nothing to “think” about: The spying happened, and it happened to me. The real question is why it happened. What drove U.S. intelligence organizations during the Obama administration to use unvetted information and inconclusive spy operations against the Republican nominee and his staff?

During my time as an adviser to the Trump campaign, federal intelligence and law-enforcement organizations used operatives to contact me in person and by email on multiple occasions. Their goal? To discuss rumored coordination efforts with Russia and extract evidence of a collusion crime.