In a speech in Wisconsin on Thursday, President Barack Obama insulted perhaps the most fervent members of his political base: art history majors. The politically clumsy moment occurred during the president’s remarks at General Electric’s Waukesha Gas Engines facility. After extolling his own economic policies at some length, Obama observed that “manufacturing jobs typically pay well” in the United States. “We want to encourage more of them,” he said. Then, he began to speak — apparently extemporaneously — about the benefits of working in America’s ever-diminishing manufacturing sector.