One of the few clear goods to have emerged from the social and political turmoil of the past decade is a collapse of faith in public opinion polls. Last fall’s off-year elections were not as disastrous for the industry as the three presidential contests that preceded them, but they still represented another blow to pollster prestige. The former governor and Democratic superhack Terry McAuliffe lost a Virginia gubernatorial race in which most outlets had shown him narrowly but consistently ahead, while in solidly blue New Jersey the Democratic incumbent, Governor Phil Murphy, barely squeaked out a win after many…