Hillary Clinton has built a commanding lead over Donald J. Trump in national polls, but she still has one big weakness: white working-class voters, especially men.
Even now, she is underperforming any recent Democratic candidate among white voters without a college degree.
It’s a very different story from 2008, when Barack Obama built a big national lead by attracting white working-class voters in states like Wisconsin and Indiana.
Instead, Mrs. Clinton’s gains come from big margins among well-educated voters and an electorate that’s much more diverse than it was even a decade ago.
The result is a sharp increase in polarization along demographic lines of race, education and gender — yet a decrease in geographic polarization. The predictable electoral map of the last four elections, born in part of the culture wars and split along familiar regional divides, might not look quite the same this November.