Rachel Maddow’s MSNBC show has become increasingly unhinged since Robert Mueller’s report got delivered to Attorney General William Barr. In fact, you’d be excused if you thought you were listening to Alex Jones, given the number of conspiracy theories being peddled. Even a writer for Slate — not exactly a hive of conservative thought — observed that the “The Rachel Maddow Show” show has become a clearinghouse for all kinds of bizarre theories. Last week was a special sort of crazy for Maddow, however. Not only did she peddle an absolutely false narrative about Attorney General Barr on Friday, she...