The House Intelligence Committee memo about 2016 surveillance abuses, released Friday, lays out grave evidence that the FBI wasn’t fully forthcoming with the Foreign Intelligence Surveillance Court as it sought an order to wiretap former Trump adviser Carter Page. It’s possible the FBI’s lack of candor was even worse than the memo describes.

Democrats are disputing the memo on lots of grounds, but they’ve said little about the FBI’s failure to inform the court that the bureau had itself decided one of its main sources, dossier...