Wisconsin offers a good illustration of place-based partisan evolution. The state has been decided by less than one percentage point four times in the past six elections, but the distribution of votes has changed immensely in that period. In 2000, Al Gore won the largest county, Milwaukee, by about 20 percentage points and eked out a 5,000-vote victory in rural areas such as Pepin County, the birthplace of the Little House on the Prairie author, Laura Ingalls Wilder. In white, wealthy suburban areas such as Waukesha, he got clobbered by more than 30 points. This year, Biden doubled Gore’s margin in Milwaukee to 40 points and significantly narrowed the gap in Waukesha, while Trump cleaned up in Pepin. Thus, two Democrats separated by two decades won Wisconsin by less than 0.5 percent—Gore with a metro-rural coalition and Biden with a big metro surge that carried over into the white-collar suburbs.
This story is playing out across the country. The economist Jed Kolko calculated that, as of midday yesterday, large urban areas remained staunchly pro-Democrat as inner suburbs moved hard to the left. In the Northern Virginia suburb of Fairfax, just across the river from Washington, D.C., Biden won 70 percent of the votes in a county that George W. Bush carried in 2000. Meanwhile, Kolko found, Trump held on to a 40-point lead in rural America and gained votes in low-density suburbs, such as Ocean, New Jersey, outside New York City. From coast to coast, inner suburbs are voting more like cities—that is, for Democrats—and outer suburbs are voting more like rural areas, for Republicans.
Driving both the polarization of place and the depolarization of race is the diploma divide. Non-college-educated Latino and Black Americans are voting a little bit more like non-college-educated white Americans, and these groups are disproportionately concentrated in sparser suburbs and small towns that reliably vote Republican. Meanwhile, low-income, college-educated 20-somethings, many of whom live in urban areas, are voting more like rich, college-educated people who tend to live in the inner suburbs that are moving left.