Residential segregation by race is a large issue and voting patterns in recent elections generally show Democrats winning in cities and close suburbs and Republicans winning in outer suburbs and rural areas. Put these two ideas together and you have residential segregation by political party.

As new research has found, it’s not just that many voters live in neighborhoods with few members of the opposite party; it’s that nearly all American voters live in communities where they are less likely to encounter people with opposing politics than we’d expect. That means, for example, that in a neighborhood where Democrats make up 60 percent of the voters, only 50 percent of a Republican’s nearest neighbors might be Democrats.

Democrats and Republicans are effectively segregated from each other, to varying degrees by place, according to the Harvard researchers Jacob Brown and Ryan Enos. And at least over the past decade, they believe this partisan segregation has been growing more pronounced…

For each individual voter, tied to an address, the researchers looked at their thousand nearest voters, weighting those next door more heavily than those a mile away. Drawn this way, about 25 million voters — urban Democrats especially — live in residential circles where at most only one in 10 encounters is likely to be with someone from the opposite party. Democrats in parts of Columbus, Ohio, and Oklahoma City live this way. So do Republicans in the reddest parts of Birmingham, Ala., and Gillette, Wyo…

These studies together suggest that as places become more politically homogeneous, people there are more likely to conform and to publicly signal their partisanship. Maybe no one says, “I want to move here because of all these Biden yard signs.” But perhaps one neighbor is swayed by the people who put them up, and another neighbor concludes, “This isn’t the place for me.”

Lots of confounding variables to examine across a lot of locales. But, the underlying patterns are fascinating to consider: do geographic communities, even in an era of reduced neighborly contact and participation in local institutions, influence people’s political belief and behavior? With more focus in recent years on how online and social media behavior influences politics, this connection to geography has the opportunity to reinvigorate conversation about the power of local communities.

I would be interested to see how this plays out among local governments of communities with similar traits. Take a suburb closer to a big city that leans Democrat and a suburb further out that leans Republicans. Are the local decisions made that different? Do local elections look different?

Or, how often are there tipping points across communities and neighborhoods where a majority of voters are of one party or another? The patterns now show some stability but these have changed in the past and could change again in the future. What happens when they do change and does the character of the community change?