The public knows that the FBI relied extensively on the Democratic Party-financed dossier, whose list of anti-Trump allegations influenced the bureau’s overall attitude toward the candidate and eventual president. Now, Attorney General William Barr has made it clear he wants to know more: Just how far did the discredited dossier take the FBI into the depths of a nearly three-year Trump investigation? “What were the standards that were applied? What was the evidence?” Mr. Barr told CBS News, adding that his focus is not on the rank-and-file but on senior FBI leaders. Dossier writer Christopher Steele, a former British intelligence...