This kind of groupthink is so powerful that it shapes the way people see the world around them. Right after the election, and more than two months before Mr Trump took office, Republicans told pollsters that their personal finances were in much better shape than they had been the week before the ballot. Democrats said the opposite. The question had nothing to do with politics, and yet the answers given were somehow conditioned by the election. To understand how this can happen, compare and contrast two congressional districts: the one that is heading Republican fastest, and its Democratic counterpart. Conveniently, they are less than 200 miles apart.