A curious belief in some circles of journalism holds that if both sides are equally unhappy with your story, you’ve done a good job. I never subscribed to that approach, and thankfully, President Trump didn’t when it came to the performance of James Comey. The suddenly former FBI boss was long cavalier about making enemies among both Democrats and Republicans, as if going rogue repeatedly proved his rectitude. On occasion it did, but Comey increasingly wore his self-righteousness on his sleeve, confident he was too big to fire. That was his fatal mistake. And it’s why Trump made the right...