DONALD TRUMP’S surprise victory in 2016 remains a mystery to observers of American politics. One common explanation has to do with demographics. Hostility towards immigrants was central to Mr Trump’s campaign platform. It is possible that working-class whites, a key source of support for Republicans, felt threatened by the country’s growing Hispanic population and were attracted to Mr Trump’s nationalistic rhetoric.

It would be natural to assume that areas which saw the biggest influxes of migrants in recent years also saw the biggest swings in Mr Trump’s favour in 2016. Yet a new paper by Seth Hill, Daniel Hopkins and Gregory Huber, three political scientists, shows this is not so. By combining election data from 26,000 precincts in seven different states (each of which can be as small as just a few city blocks) with demographic information from the census, Mr Hill and his colleagues were able to study the topic in more detail than ever before. They find that, if anything, regions which saw bigger immigration flows actually swung against Mr Trump in 2016, though the effect is small: a 3.8% increase in a precinct’s Hispanic population from 2011 to 2016 corresponded with a rise of 0.2 percentage points in Hillary Clinton’s vote share.

Some pundits have suggested that “economically anxious” voters were especially susceptible to Mr Trump’s anti-migration rhetoric. Messrs Hill, Hopkins and Huber find no evidence to support this theory. Immigration rates were still slightly positively correlated with increases in Democratic vote share, even in the poorest parts of America. The authors also found that precincts with more non-citizen—and thus non-voter—immigration shifted to the left between 2012 and 2016, showing that the overall pattern is not driven by a replacement of whites by Hispanic voters.

Past studies have nevertheless found that Americans’ attitudes to immigration are becoming more closely linked to their voting behaviour. Mr Hill and his colleagues reconcile their study with past literature by suggesting that fears of immigration stem more from popular narratives, rather than lived experiences. At the very least, this would explain why residents in the Midwest, who live in predominantly white communities, are so interested in erecting a wall some 1,500 miles away.