The Parkland shooting earlier this year seemed at last to ignite a public movement in response to these terrible crimes. Yet even the cumulative impact of slaughter after slaughter has not softened the harsh divide of the American gun impasse. Back in 2012, Nate Silver observed: “Whether someone owns a gun is a more powerful predictor of a person’s political party than her gender, whether she identifies as gay or lesbian, whether she is Hispanic, whether she lives in the South, or a number of other demographic characteristics.”

More than 70 percent of Trump voters in 2016 described guns as “very important” to their vote, versus only 40 percent who described abortion as “very important” to their vote and only 25 percent who felt that way about gay rights. With the slow fading of battles over same-sex marriage and abortion, and the rapid collapse of other aspects of conservative ideology, guns may now rank as the single most important political dividing line in 21st century America.

Only 30 percent of Americans own guns. Thus far, that minority has sufficed to block substantial federal action on guns. But a one-third minority—and especially a non-urban one-third minority—may no longer suffice to shape American culture.