I like Arthur Branch, the tough-minded district attorney I used to see on NBC's "Law & Order." I like his deep voice and his comforting Southern charm. I like his steadfast determination to seek justice and his clear sense of right and wrong. I've been less certain about Fred Thompson, the actor who played him. He mismanaged his campaign and lost a wave of momentum by delaying the announcement of his presidential bid. He traded Republican debates for late-night talk shows. He's been unspectacular on the campaign trail. But this week, something happened that's making me reconsider my assessment of...