THIS week’s Lexington column is on the “marriage gap” in American politics. There are 53m unmarried women of voting age in America, and they are spectacularly loyal to Democrats. In the 2012 presidential election, unmarried women accounted for nearly a quarter of all votes cast. Their votes went decisively to Barack Obama, by 36 percentage points.

You might not think that a group that runs from not-yet-married college students to inner-city single mothers and divorced professionals had much in common. Yet strategists and pollsters report that—even after controlling for such variables as race, age, religiosity and income—marital status is a powerful predictor of Democratic voting (whereas married women and older widows lean slightly Republican). The key to the puzzle appears to involve attitudes to government safety nets, and a shared sense among unmarried women that they are trying to survive without any back-up in a harsh, increasingly insecure economy (unmarried women are disproportionately likely to work in jobs which do not offer health cover, for instance). Put another way, the conservative battle-cry of “Leave me the Hell alone” sounds different when you are literally on your own.