Read: Why white women continue to back the GOP

In both parties, most strategists I’ve spoken with agree that Trump’s bellicose attacks on the congresswomen will harden the opposition he faces among the groups most accepting of America’s changing identity: young people, minorities, and college-educated white voters, especially women. What’s more, his new offensive represents exactly the sort of behavior that has led an unprecedented number of voters satisfied with the economy to nonetheless express doubts about his leadership: In an NPR/PBS NewsHour/Marist College poll released earlier this week, fully one-third of adults who said the economy is working for them personally still said they disapprove of Trump’s job performance. An equal share of these voters said they now intend to vote against him for reelection. To offset that unusual defection among the economically content, Trump must maximize his margins—and turnout—among the groups that have been most receptive to his exclusionary racist and cultural messages: older, nonurban, evangelical-Christian, and non-college-educated white voters.

Democratic strategists generally believe that Trump’s rhetoric will likely cost him more than it gains him in the total popular vote. But the past week has produced a collective spasm of anxiety in Democratic circles that his new attacks could nevertheless help him win a second term because the working-class whites believed to be most receptive are overrepresented in the three most crucial states: Pennsylvania, Michigan, and, above all, Wisconsin. (In the last state, non-college-educated whites cast fully three-fifths of all votes in 2018, according to the Census Bureau, more than in any other swing state.)

But Trump’s strategy faces a huge obstacle if working-class women don’t buy in to his message as much as working-class men. That’s for a simple reason: Every data source—from the exit polls to the Pew Research Center’s analysis of voter files to studies by Catalist, a Democratic voter-targeting firm—shows that these women reliably cast slightly more than half of all the votes from the white working class.

“If you think about the strategy they had in ’16 … where he campaigned and went into these [blue-collar and nonmetropolitan] areas and really drove up the vote—that doesn’t work if the women aren’t responding to it, if they watch him and they get put off by it,” Greenberg says. “It only works if women are part of the story. You just can’t get the numbers if half of white working-class, nonmetro voters are put off by what you are doing.”

White working-class women have been a reliably Republican-leaning constituency for the past generation. Bill Clinton in 1992 and 1996 is the only Democratic presidential candidate since 1980 who has carried them. Data measuring the 2016 vote show that Trump expanded the GOP margins with these women to the highest level in years: His advantage ranged from 21 percentage points, according to calculations by Catalist; to 23 points, according to Pew; to 27 points, according to the exit polls.