As an unabashed and high-profile liberal on President Barack Obama’s White House staff, former “green energy” czar Van Jones was to Republicans what a red cape is to a snorting bull: an irresistible target. So when he resigned in 2009 under withering fire from the right — triggered by a video of him disparaging the GOP, followed by revelations of a tenuous connection to Sept. 11 conspiracy theorists — few doubted Jones was finished in Washington. He acknowledged as much a year later, writing in The New York Times that politics has become “a combination of speed chess and Mortal...