By Charles Lane

“You are now free to move about the country” is not just a memorable advertising tag line from Southwest Airlines but a fair assessment of the actual residency choices available to millions of Americans.

As a result, U.S. politics might be changing in subtle but — knock on wood — potentially stabilizing ways.

Specifically, the “Big Sort” might have finally peaked. First identified in a 2004 series of articles by political analyst Bill Bishop, the “Big Sort” was the decades-long trend whereby like-minded Americans increasingly clustered geographically. That contributed to destructive polarization between an increasingly conservative red America and an increasingly liberal blue America.

Yet, a close look at the Census Bureau’s latest estimate of national and state populations, along with other data, yields at least some hope that Americans are starting to reshuffle themselves. The report, released Dec. 30, was the last “intercensal” study before the actual headcount in 2020 and especially indicative as a guide to congressional reapportionment over the coming decade.

The numbers suggest that states that President Donald Trump carried in 2016 will gain a net three seats in the House of Representatives as of 2022, and, as of 2024, three presidential electoral votes, while states that Democrat Hillary Clinton carried will lose three House seats and three electors, according to a breakdown of the census report by election analyst Sean Trende of RealClearPolitics.

Among the biggest winners, potentially, are deep-red Texas, on track to gain three House seats, and Florida, which could gain two. The three largest blue states, California, New York and Illinois, meanwhile, are likely to lose one each (setting up potentially nasty quarrels among Democrats over which incumbent will lose out in redistricting).

So far, so good for the GOP. Much of the shift, moreover, seems to represent movement from high-tax, high-regulation urban areas, where housing is increasingly expensive, to sprawling metro areas in the Sun Belt. California alone saw net domestic out-migration of 203,414 between 2018 and 2019, and if recent trends are any indication, many of these folks wound up in Trump states.

Conservatives have even coined a new word for these people: “leftugees.” As the moniker implies, Republicans are inclined to declare ideological victory, given that so many people seem to be voting with their feet against blue America’s policies. The conservatives have a point. But the fact that leftugees move in pursuit of more-affordable housing or to escape chronic traffic jams does not mean they all prefer a pure “red” policy model of low taxes and fewer services. To the contrary, blue-state migrants may nudge the politics of their new homes leftward, while avoiding the worst liberal excesses they left behind.

In-migration from blue states is a big part of what turned Colorado from red to purple to a moderate shade of blue in recent decades. The state experienced a net inflow of more than 100,000 people from California, New York and Illinois between 2010 and 2016, according to the Kansas City Federal Reserve Bank.

The problem, for Democrats, of an electoral college that “wastes” votes in California or New York remains, barring a constitutional amendment. The Senate — which cannot be amended away — still favors rural red America.

Sooner or later, though, a critical mass of blue Americans may figure out that there is another way to gain political clout: move.

Charles Lane is a Washington Post opinion writer.