True swing voters are extraordinarily rare in America

The biggest question in American politics today is why Joe Biden’s support is so soft. Although there are plenty of theories—ranging from Mr Biden’s age to petrol prices to the withdrawal from Afghanistan—it is hard to be confident about an answer. A standard poll of the type quoted in news reports may be based on a sample of 1,000 people. A poll that asks questions of voters in a swing state might have half that number. These yield useful information, no doubt, but if you want to look within those polls at what, say, , the numbers are too small to draw conclusions. . Over the past year, YouGov has posed questions to a total of 49,000 Americans of voting age. If you pool their answers, as we have this week, you can discover what is really going on.Because most American voters are partisan and opinions about the two candidates are so calcified, very few people who voted for Joe Biden in 2020 will in November, or vice versa. In a , swing voters have double value because they subtract from one side and add to the other. Finding them, though, is like hunting for four-leafed clovers.