New state-level population estimates released by the U.S. Census Bureau in January suggest the country could see big changes in representation and political power following the reapportionment of seats in the House of Representatives that will take place after the 2030 census.
But perhaps more than any time in recent history, there is considerable uncertainty about the extent to which these projections will bear out due to potential long-term changes in immigration levels and other possible demographic shifts.
Another Landmark Decade for the South and Mountain West?
Halfway through the decade, the new data suggests that the next reapportionment should, in theory, produce yet another blockbuster gain in congressional seats for the South – possibly the region’s biggest ever.
Assuming that population trends since 2020 continue for the rest of the decade, Florida, Georgia, North Carolina, and Texas are all expected to pick up congressional districts in the next reapportionment. Florida and Texas would be the biggest gainers, with four and three new districts respectively, while Georgia and North Carolina would each add a seat.
If these estimates come to pass, the South would have more seats in the House than at any point in its history, with southerners making up nearly 40 percent of the body’s membership.
Growth trends since the 2020 census also suggest that states in the Mountain West would be big winners in reapportionment, with Arizona, Idaho, and Utah each picking up a new district.
Meanwhile, states of the Northeast and Midwest would continue a trend dating back to the post–World War II era of losing seats in once-a-decade reapportionments. While New York and Illinois had 45 and 27 congressional seats respectively after the 1930 census, they would have just 24 and 17 after the 2030 reapportionment if current projections hold.
In the West, California also would see a stunning loss of representation, seeing its congressional delegation decrease by 4 seats to 48 seats, only the second time it has lost representation since statehood. Likewise, Oregon, which was one of 17 states with more deaths than births between 2024 and 2025 and has come to rank near the bottom in terms of both immigration and domestic migration, would lose the district it only just picked up in the 2020 reapportionment.
Notably, however, the new data does reflect some uncertainty for Florida. Based on census data released in December 2024, Florida had been expected to gain four new seats after the 2030 census. This year, with slowing population growth, that estimated change has fallen to three seats. In fact, using just the population trend from the past year to project future growth, the Sunshine State would gain only two new seats (while New York would lose only one rather than two).
The Caveats: Past Is Not Necessarily Prologue
As the example of Florida shows, projections of future population growth come with an important proviso: Future population changes may not look like the past.
Perhaps the biggest and most obvious uncertainty centers on what future levels of immigration to the United States and its composition will look like.
In recent years, as the native-born U.S. population has become older, immigration rather than population increase from births become an increasingly big component of U.S. population growth, in both blue and red states.
In fast-expanding Texas, for example, immigration accounted for 44 percent of the Lone Star State’s population growth between 2024 and 2025, a larger share than came from either domestic in-migration or natural increase (births).
Similarly, in the same period, immigration accounted for more than 90 percent of Florida’s growth. While Florida added 178,674 immigrants from outside the United States to its population between 2024 and 2025, only 22,517 people (barely a tenth of the state’s new immigrant population) moved there from other parts of the United States last year. (As a state with a significant population of retirees, Florida has long had more deaths than births each year.)
California, Illinois, and New York, likewise, all would have seen a net loss in population during the period had it not been for immigration.
The role of immigration as a driver of population growth was especially pronounced during the first three years of the Biden presidency when the clearing of pandemic-era visa backlogs and a spike in the number of people seeking admission to the country on humanitarian grounds (i.e., seeking entry as refugees or applicants for asylum) helped to offset a nearly two-decade decline in births and an increase in deaths among the giant but aging cohort of Baby Boomers.
However, recent or even historical immigration levels may not be a good guide to the future.
Since taking office in January 2025, the second Trump administration has pursued much more restrictive immigration policies, the contours of which are still evolving. Not only has it sharply reduced the number of people being admitted for humanitarian reasons, but it has stepped up deportation efforts, including of many long-term residents, and taken steps for the first time in six decades to curtail other legal routes of entry to the United States, such as student and work visas.
As a result of these changes, most experts now expect immigration to the United States will be flat for at least the next several years. Some experts think immigration levels might even be net negative, with more people leaving the country than entering — something that hasn’t happened in at least six decades.
These reduced levels of immigration are only partially reflected in new census data, which only measures population change through July 1, 2025.
If, in fact, immigration levels turn out to be zero or negative for the balance of the decade, the current reapportionment projections could be impacted in unexpected ways. For example, with zero immigration between 2025 and 2030, the Brennan Center projects that Florida would gain only two seats rather than three because it would go from being one of the nation’s fastest growing states to a relatively slow growing one. Meanwhile, Wisconsin would keep a seat that it is currently projected to lose.
And importantly, reduced levels of immigration mean not just fewer people arriving in the United States each year, but fewer births since immigrants tend to be younger in general than native-born Americans. An early set of Census Bureau estimates of long-term population growth, for instance, projected that without immigration, the number of deaths in the United States would begin to exceed births in 2033 rather than 2038, putting the United States on par with low-immigration countries in Europe and Asia.
Add to the mix a further complexity: uncertainty about whether future reductions in the level of immigration will be uniform across the nation or will vary among states as certain types of immigrants (high-tech workers or medical professionals, for example) continue to be allowed in while others are not.
But changes in immigration levels aren’t the only thing that could cause a shift in reapportionment projections. The rate of domestic migration — that is, the number of people who move from one state to another during the course of a decade — also could change.
For many states, migration to or from the state is a big driver of change. But the rates of domestic migration can also vary over time, and trends of recent years may or may not hold for the second half of the decade.
For example, one recent analysis suggests that Florida, long a magnet for retirees, is becoming unaffordable for many working and middle-class seniors. Rising housing costs in the boom states of the South, coupled with higher interest rates, could also slow growth in those dynamic states.
Finally, whether the next reapportionment ends up in line with projections will depend on a full and accurate census in 2030. This, in turn, will depend both on whether the federal government and states avoid pitfalls of the past.
Take the 2020 census. In the lead-up to it, California spent $187 million and New York State and New York City collectively spent $100 million encouraging residents in hard-to-count communities to fill out census forms and ensuring them of the security of their personal data. By contrast, fast-growing and diverse Texas spent no state funds on census outreach, despite having sizeable immigrant and other hard-to-count communities. The result was a reapportionment surprise. Undercounts meant that Arizona, Florida, and Texas each received fewer new congressional seats than expected in the 2020 reapportionment, while states like New York and Minnesota retained seats they had been projected to lose.
Likewise for the 2020 census, Congress funded census operations at levels well below what many census advocates felt was necessary to maximize a full count. On top of that, the first Trump administration made a controversial, last-minute decision to try to add a citizenship question to the census questionnaire, despite advice from experts that an untested citizenship question could depress turnout in states with large numbers of immigrants.
There are already signs of a possible repeat, one that might be even more egregious. Though efforts to add a citizenship question to the 2020 census were blocked by federal courts on grounds that the administration hadn’t followed the required procedures in trying to get it added, it could yet return this decade. Indeed, congressional Republicans have introduced bills not only to add a citizenship question to the 2030 census but also to require respondents to state whether they have a lawful right to be present in the United States. The bills would then purport to require subtraction of any persons without legal status from statistics used for reapportionment.
Likewise, while states like New York have already taken steps toward planning for the 2030 census, now less than four years away, many other states, like Texas, have not. In an atmosphere where distrust of the government is growing across the political spectrum, this may not bode well for the accuracy of the next census.
