While the mainstream news media hunts for evidence of Trump-Russia collusion, the public record shows that Democrats have willfully used Moscow disinformation to influence the presidential election against Donald Trump and attack his administration.The disinformation came in the form of a Russian-fed dossier written by former British intelligence agent Christopher Steele. It contains a series of unverified criminal charges against Mr. Trump’s campaign aides, such as coordinating Moscow’s hacking of Democratic Party computers.Some Democrats have widely circulated the discredited information. Mr. Steele was paid by the Democrat-funded opposition research firm Fusion GPS with money from a Hillary Clinton backer. Fusion...