It’s Not Just the Weather: People Are Moving to Red States

A county-level model shows that differences in climate and general development patterns do not fully explain the migration advantage seen in red states.

Over the past five years, domestic migration within the United States has followed a clear and consequential pattern: population growth has been consistently stronger in Republican-leaning states than in Democratic-leaning ones.

That pattern is often explained away as a byproduct of geography rather than political factors. Warmer climates, lower density, and suburban or rural lifestyles have long attracted movers, particularly in the Sun Belt and Mountain West. On its face, that explanation is intuitive, but it is incomplete.

Using county-level data, I examined domestic population change while accounting for several of the most commonly cited drivers of migration. I incorporated local climate by collecting average January high temperatures for every county, controlled for development patterns using population density (measured as median weighted census block group density), and accounted for demographic factors. These adjustments capture much of what we would expect to explain migration trends: people tend to move toward warmer, less dense areas, and population change varies meaningfully across demographic compositions.

Even after accounting for climate, density, and demographics, a substantial gap remains. Figure 1 shows the model-implied difference: counties in Trump-won states were still predicted to experience roughly 2.7 percentage points more domestic population growth over the past five years than otherwise similar counties in Trump-lost states. That does not, by itself, establish that partisan governance is the cause. But it does suggest that the divergence is not simply a story about warm weather, suburbanization, or demographic composition more broadly.

There is no single agreed-upon explanation. Instead, the debate tends to cluster around a few competing theories.

One argument, often advanced by center-left housing-focused policy analysts, centers on housing constraints. In many Democratic-leaning states, particularly in large metropolitan areas, housing construction has lagged demand for years. Restrictive zoning and local opposition to development have limited new supply, making sustained population growth more difficult. In that framework, out-migration is less a matter of preference than of affordability.

A second explanation, often offered by conservatives, focuses on public safety. Some observers point to differences in crime rates as a potential driver of migration decisions. While there are measurable differences across states, those gaps are more modest than often perceived once demographic and economic factors are taken into account. Even so, perceptions of safety can influence behavior independently of the underlying statistics, and may play a role at the margin.

A third line of argument, also offered by conservatives, emphasizes fiscal policy. Higher taxes and cost of living in certain states are frequently cited as reasons individuals and businesses relocate elsewhere. Whether these factors are decisive or simply contributory remains an open question, but they are consistently part of the broader narrative.

It is difficult to disentangle these mechanisms cleanly, and I do not want to attempt to assign causal weight to any single explanation because it’s not my expertise. What it does establish, however, is that the divergence in population growth between Democratic- and Republican-leaning states persists even after accounting for many of the most obvious structural differences between them.

Appendix: Full Regression Results