Former special counsel Robert S. Mueller III, at long last, testified before Congress about his investigation into Russian interference and President Trump’s conduct related to it. Mueller appeared before the House Judiciary Committee in the morning and the House Intelligence Committee in the afternoon. Here’s what we learned from both sessions. 1. Mueller struggled If Democrats hoped this would be a seminal moment, they will apparently leave sorely disappointed — in large part because their star witness was no star. Mueller spoke haltingly, seemed not to remember key details and tripped over himself even when members weren’t trying to trip...