The White House is dispatching Michelle Obama to serve as Grand Marshal of the Nov. 20 season-ending NASCAR Ford 400, a move that seems clearly designed to woo NASCAR voters while also burnishing the first lady’s credentials as a regular gal. Mrs. Obama, who has incurred some bad publicity for taking luxurious jaunts to South Africa and Spain while often being photographed in expensive clothing and accoutrements, has lately been spotted shopping at Target and hanging out at the baseball park, attending the first game of the World Series. The NASCAR appearance is billed as part of the first lady’s...