Maine's far-left Democratic Senate nominee, Graham Platner, has leaned on his career as a "working-class" oyster farmer to cast himself as a blue-collar everyman. His Ivy League business partner—who owns the secluded island where the farm is based—is, well, anything but. Robert Cushman III is an elite New England boarding school graduate who has described his habit of drinking "foraged spring water with Redmond sea salt." He got into the oyster farming business, he has said, after having had a "