In January, as Bernie Sanders was surging in the polls, many pundits claimed he had a real chance at the nomination. After Iowa and New Hampshire, his probability of winning it, according to RealClearPolitics.com, was more than 50 percent. When Mr. Sanders won the Nevada caucus by a large margin, some people claimed the nomination was all but his.
I was skeptical — because of race. A few days before the Iowa caucus, I wrote that even if Mr. Sanders won the first two contests, the huge black vote in South Carolina would stop his winning streak. I pointed out that Barack Obama, who like most blacks doesn’t care for the democratic socialist from Vermont, could endorse Joe Biden at any time if the former vice president needed a boost from blacks. ...