Jenny Sanford, ex-wife of disgraced former South Carolina Gov. Mark Sanford, steps into the GOP presidential primary fray with an op-ed Thursday praising Herman Cain. Ms. Sanford says she hopes Mr. Cain will keep fighting for his far-reaching tax overhaul plan even as he fends off what she calls personal allegations enflamed by the media. “I know this story well,” she writes in The (Columbia) State newspaper. “A ‘fresh face’ appears on the political scene and puts forth new proposals that challenge the status quo and then is attacked viciously on his proposals and then his character.” That sounds like...