We live in an age of unbridled white id. Many days it is anything goes, baby, from the White House to the baseball stands; objecting often draws a scornful wave of the hand and a lecture on political correctness. The latest eruption comes courtesy of Josh Hader, a 24-year-old white relief pitcher with a smoking fastball and a Twitter account filled with hideous thoughts typed when he was 17 and 18. A Hader sampler: “White Power, lol” (with an emoji of a clenched fist), “KKK,” and “I hate gay people.” He also used that vilest of words for black people....