Red states are getting redder. Blue states are getting bluer. Is it any surprise that our politics are getting hotter? An exclusive USA TODAY analysis of the nation's 3,113 counties shows a striking realignment since 2012 that has intensified the partisan leanings in states across the country, leaving only a handful where the outcome of the Nov. 5 presidential election remains in doubt. The hardening of the country's political lines has contributed to other consequences, too, including one-party control of the governorship and state legislature in 40 of the 50 states. That has led to a patchwork of sharply divergent laws across the country − even between neighboring states − on abortion rights, transgender care, the public-health response to the pandemic and other controversial issues.

Most Americans nationwide − a 55% majority − said it was very or somewhat important to them to live in a community that shared their general political views. Indeed, 7% said they had moved to a new community to be around more like-minded neighbors. But an even larger majority, 60%, said it was very or somewhat important to them to live in a community with a diverse population, including those who don't share their general political views. More than 1 in 10, 12%, said they have moved to a new community in search of more diversity. On this, as on many things, there was a partisan divide. Republicans were more likely than Democrats to say it was very important to be in a community with those who shared their general political views, 24% versus 18%. In contrast, Democrats were almost three times more likely to say it was very important to be in a community with diverse political views, 30% versus 11%. The nationwide poll of 1,000 likely voters, taken Aug. 25 to 28 by landline and cellphone, has a margin of error of plus or minus 3.1 percentage points.

Those who have moved to more diverse communities included 18% of 18- to 34-year-olds; they are in a time of life when many young people are deciding where to settle. They also included 17% of Democrats but just 5% of Republicans. In the Arizona and Florida polls, the top reason cited for moving to those states was family considerations (37% and 47%), followed by jobs (32% and 22%). In Florida, the weather was also a major factor for 23%. The USA TODAY/Suffolk polls of 500 likely voters in each state, taken by landline and cellphone, have error margins of 4.4 points. The Arizona survey was taken Sept. 21 to 24 and the Florida survey Aug. 7 to 11. Politics played a role as well. Fifteen percent of those who moved to Arizona said it was because the state was "better fit for you and your values." Eleven percent of those who moved to Florida cited the same reason. On the other side, 8% of those now living in Florida said they planned to move out of the state over the next four years. The top reason? "Politics/DeSantis," a reference to conservative Republican Gov. Ron DeSantis, was volunteered by 40% of them.

"Overall, you have to wonder if these movements of people are nothing more than a mobilization toward a new sort of civil war," said David Paleologos, director of the Suffolk Political Research Center. "Not the kind of civil war with militias and muskets, but a quiet separation from fellow Americans living in the state next door where life, laws, and political reality are worlds apart."

- Seventy-three percent of counties became more partisan from 2012 to 2020, including 224 blue counties that got bluer and 2,050 red counties that got redder. (The disparity in number isn't as stark as it sounds. The red counties were often in sparsely populated rural areas; the blue counties were often in densely populated cities and suburbs.)
- Overall, 40 states became more partisan − that is, states in which partisan leanings intensified in more than half the counties. The exceptions were Delaware, Hawaii, Maine, New Hampshire, New Jersey, New York, South Carolina, Utah and Vermont. Alaska wasn't included in the analysis because it reports by election districts, not counties.
- Fewer than 1 in 5 counties, 19%, became less partisan over that time, trending less blue (264 counties) or less red (317 counties). In other words, by almost 4 to 1, counties became more partisan, not less so.
- Just 8% of counties changed colors, 50 red counties turning blue and 208 blue counties turning red.
- Even fewer ‒ 5% of counties, 161 of them ‒ were decided in 2020 by 5% of the vote or less, making them relatively competitive.