CNN  — 

The battleground states across the industrial Midwest have functioned as the decisive tipping point of American politics for at least 30 years, especially in presidential elections. But the latest Census Bureau findings on both overall population growth and voter turnout in 2020 signal that the Sun Belt will increasingly rival, and potentially replace, the Rust Belt as the central battlefield in US elections.

Continuing a decades-long trend, the latest census numbers on total growth show a shift in population, and with it Electoral College votes and seats in the House of Representatives, away from Rust Belt states in the Northeast and upper Midwest – such as Ohio and Pennsylvania – toward Sun Belt states across the South and West – like North Carolina, Texas and Colorado.

Simultaneously, the new census results on voting show that compared with the Rust Belt, the electorate in the Sun Belt is evolving more rapidly in a direction that benefits Democrats, with a growing share of non-White voters and a shrinking share of blue-collar Whites. That means the Sun Belt states, most of which leaned solidly Republican until recently, are likely to grow more competitive, even as their clout in the House and Electoral College steadily increases.

While the Rust Belt states are likely to remain closely contested in presidential elections as well, the continued dominance there of blue-collar Whites, who have emerged as the undisputed cornerstone of the GOP coalition in the Donald Trump era, could make those places more difficult over time for Democrats to hold, particularly if the party transitions to a more racially diverse cast of national leaders after President Joe Biden.

As the Rust Belt states become more challenging and the Sun Belt states more influential, the Democrats’ ability to compete for the White House and control of Congress through the 2020s may increasingly turn on whether the party can continue the advance across the region that brought breakthroughs first in Colorado, Virginia and Nevada and more recently in Arizona and Georgia.

“Demographically it’s just going to be harder and harder to win those Rust Belt states,” says Democratic consultant Abhi Rahman, former communications director for the Texas Democratic Party. “What’s going to happen after Biden? You are going to need someone who is going to be able to expand the map and win some of those other [Sun Belt] states.”

The big new census reports on population trends and voter turnout in 2020 each show the continuation of core underlying trends reshaping the electoral battlefield.

In terms of overall population, the key trend is the ongoing shift of American population toward states in the South and West. Though the years from 2010 to 2020 produced a slower level of total population growth than any other decade in American history except the Depression years of the 1930s, the increase that did occur tilted heavily toward the states in the Sun Belt.

In his recent analysis of the census results, William Frey, a demographer at the Brookings Institution’s Metropolitan Policy Program, found that only 13 states experienced double-digit increases in their populations over the past decade. Of those 13, all but North Dakota and Delaware are in the South and the West; the others are (in order of their growth rates, starting with the fastest) Utah, Idaho, Texas, Nevada, Colorado, Florida, Washington, Arizona, South Carolina, Georgia and Oregon.

Biggest population gains in Sun Belt

Another revealing measure is the absolute number of people each state added. Again, the Sun Belt dominated on that metric. Of the 17 states that added the most new residents from 2010 to 2020 (at least 404,000 in each case), Frey found, 14 are located across the South and West. The Sun Belt provided all six of the states with the largest absolute gains (with Texas at 4 million and Florida at 2.7 million topping the list) and 11 of the top 12 (with only New York breaking the string). In the Rust Belt, the numbers were much more modest.

Apart from Massachusetts (at a relatively robust 482,000) none of the other New England states gained more than 61,000 new residents; apart from Minnesota (at just over 400,000), growth was also modest in the key states across the industrial heartland. West Virginia’s population declined by almost 60,000, the biggest loss of any state.

As Frey noted, this continues the long-term trend of population shifting from the Northeast and Midwest toward the South and West. In 1920, he calculates, the Northeast and Midwest accounted for fully 60% of the nation’s population, with the South and West a clear minority at 40%. By 1980, the South and West had edged past the Northeast and Midwest to become the majority, and the trend has continued unabated since: The latest results, Frey shows, essentially reverse the 1920 balance, with the South and West now accounting for 62% of the US population and the Northern regions just 38%.

“The South and West’s 2010s population growth of 10.2% and 9.2%, respectively, far outpaced the Midwest (3.1%) and Northeast (4.1%),” Frey wrote. “Moreover, several Sun Belt states improved their population size rankings over the decade: Florida overtook New York to become the third-largest state; Georgia and North Carolina overtook Michigan to become the eighth- and ninth-largest states; and Arizona overtook Massachusetts and Indiana to become the 14th-largest state.”

These population trends will immediately translate into a reallocation of political influence. All six of the states that will gain congressional seats (and thus also more Electoral College clout) are in the South and West, with Texas the only state gaining two. Of the seven states that will each lose a single seat, all but California are in the Northeast and Midwest.

Over the final decades of the 20th century and the first decade-plus of this one, analysts and political strategists would have termed that shift in regional influence an unequivocal benefit for Republicans. During that long stretch, most of the South and West reliably voted Republican in presidential elections, apart from the West Coast states of Washington, Oregon and California, which have voted uniformly Democratic since 1992. By contrast, over the second half of that long period, Democrats ran much more competitively across the big industrial states across the Rust Belt, carrying Michigan, Pennsylvania and Wisconsin in all six elections from 1992 through 2012, and Ohio four times during that span.

But on each side of the regional divide, the partisan equation is less straightforward now, and population trends in both places are a significant reason why.

Since the Barack Obama years, Democrats have established a beachhead in several previously Republican-leaning Sun Belt states. The biggest changes have come in Colorado and Virginia, which have evolved from ruby red to purple to blue, and North Carolina, where Democrats have recorded more intermittent gains. In each state, Democrats advanced behind the same formula: a growing minority population coupled with enough improvement among college-educated White voters to overcome big GOP margins among Whites without college degrees (that usually exceed their advantage with those voters in Northern states). Democrats have followed the same formula to gains in Arizona and Georgia.

Though Republicans retain at least a slight edge in many of the Sun Belt states, the growth in them is occurring primarily in places, and among groups, that lean Democratic. The Census Bureau hasn’t yet released its final 2020 data documenting where the growth occurred within the states, but all the findings from other data sources over recent years show that large metro areas will be the principal source of that increase, especially in the Sun Belt.

In a recent report, the LBJ Urban Lab at the University of Texas at Austin noted that census reports place the Dallas-Fort Worth, Houston and Austin metro areas among the 10 fastest-growing in the US; those three metros alone accounted for 71% of the jobs created across the state in 2019, the group found. Large metros are similarly dominant in the growth of Sun Belt states from Colorado (Denver), Nevada (Las Vegas) and Arizona (Phoenix) to Georgia (Atlanta) and North Carolina (Charlotte and Raleigh).

Democrats’ strength growing in Sun Belt

One of the most important political trends of roughly the past decade is the growing Democratic strength in these large Sun Belt metros, which house many of the diverse and well-educated voters the party now relies on. Starting with Obama in 2008 and 2012, but accelerating in the 2016 and 2020 elections with Trump as the GOP’s standard-bearer, Democrats have extended deeper into the Sun Belt the gains in central cities and inner suburbs that they began recording in other regions during the 1990s.

In 2020, Joe Biden became the first Democrat to carry Maricopa County (centered on Phoenix) since 1948 and also ran up huge margins in the central cities and inner suburbs of Denver, Northern Virginia, Atlanta, Charlotte and Raleigh. In Texas, according to calculations by Robert Lang, a professor of urban affairs and public policy at the University of Nevada Las Vegas, Biden carried all four of the state’s large metro areas, something no Democratic presidential candidate had done since favorite son Lyndon Johnson in 1964.

Trump amassed huge advantages in small-town and rural parts of all those states, and that was enough for him to hold North Carolina and Texas by bigger margins than expected. Improvement with Hispanic voters compared with 2016 also strengthened Trump’s position in several of the key Sun Belt states (especially Texas and Florida, where he actually improved relative to 2016 in three of the four largest metro areas, Lang found).

And particularly along the Southern edge of the Sun Belt, Republicans also run better among college-educated White voters than they do along the coasts or in the upper Midwest (although Democrats are improving with them in Sun Belt states too). But the rising metro tide still carried Biden to breakthrough victories in Arizona and Georgia, states that had leaned reliably red for most of the previous four decades, and also have allowed Democrats to capture all four of their Senate seats. Similarly, Democrats now hold all eight of the Senate seats from four Southwest states – Arizona, Nevada, New Mexico and Colorado – for the first time since 1941, as I’ve written.

As with geography, the demographic changes in these states also bend toward Democrats. When the full census data is released, it’s likely to show that most of the population growth in the fast-growing Sun Belt states occurred among Hispanic, Asian American, mixed-race and in some places Black communities. And while the electorate changes more slowly than the general population (because turnout is generally higher among older and White voters than among younger and non-White voters), inexorably shifts in the latter reverberate through the former.

That’s apparent in the other major report the Census Bureau recently released, which explored voter turnout in 2020.

The biggest finding in that new census study was that Whites without college degrees, the group that has become the undisputed foundation of the Republican coalition in the Trump era, fell below 40% of the national vote for the first time, according to Frey’s analysis of the results. Those non-college Whites composed 51.5% of voters in census figures as recently as 2004 but slipped below a majority in 2008 (almost certainly for the first time in American history) and, after a steady decline through the subsequent elections, dipped to 39.7% of the total vote in 2020.

Over that same period, from 2004 to 2020, Whites with college degrees – a closely contested group that leaned slightly Democratic in 2020 – grew from just under 28% of the vote to slightly more than 31%. The biggest growth occurred among voters of color: They rose from just under 21% in 2004 to fully 29% in 2020.

The other major data sources offer slightly different portraits of the 2020 electorate: For instance, the exit polls conducted for a consortium of media outlets including CNN put the share of non-college Whites a few points lower and the minority share higher.

Conversely, the eagerly awaited study of voter files released Monday by Catalist, a leading Democratic targeting firm, put the non-college White share a bit higher (at 44%), with the non-White and (especially) college White portion slightly lower than the Census Bureau. Michael McDonald, a University of Florida political scientist considered one of the leading experts on voter turnout, conducts his own analysis of census data to adjust for nonresponses: He too found non-college Whites falling just below 40% of the vote, with college Whites slightly exceeding minorities among the remainder.

But all of the data sources, while starting from different points, show the same unequivocal trend: a steady decline in the share of the vote cast by Whites without college degrees (about 2 to 3 percentage points every four years), a slight increase or steady state among college-educated Whites and consistent growth in the non-White share of the electorate (at around 2 points every four years).

Decline in blue-collar Whites more consequential in Sun Belt

What makes the 2020 decline in vote share for blue-collar Whites so striking is that it occurred despite an enormous increase in their turnout. More than 64% of eligible Whites without college degrees voted in 2020, a huge jump from the slightly less than 58% who had showed up four years earlier, according to Frey’s analysis of the census figures.

Turnout rose significantly for every major group last year, the Census Bureau found, but the spike among working-class Whites represented a bigger turnout increase, in absolute terms, than occurred among college-educated Whites, African Americans or Hispanics. (Only Asian Americans rose more.) McDonald says turnout among non-college Whites last year was the highest since at least the 1988 election and likely the highest in modern times.

And yet despite that extraordinary mobilization, the share of the total vote cast by those blue-collar Whites still continued its decades-long decline. The reason is that those working-class White voters are diminishing as a share of eligible voters, as the overall population grows both more racially diverse and better-educated.

“Their higher turnout did not compensate for the shrinking size of that group,” McDonald says.

Census data analyzed by Frey shows that Whites without college degrees have declined as a share of the electorate since 2004 in every major swing state, including those across the Rust Belt. But in three distinct respects, the changes in the electorate’s composition are more consequential in the Sun Belt.

One is the sheer pace of change. In most of the key Rust Belt states (including Michigan, Pennsylvania, Ohio, Iowa and Minnesota), the share of the vote cast by non-college Whites declined by 9 to 11 percentage points from 2004 to 2020 (in Wisconsin it fell by just 7 points). By contrast, the falloff was somewhat greater in many of the key Sun Belt states (including Arizona and Nevada, at more than 16 percentage points, and Colorado and North Carolina, at 11 to 12 points).

A more important difference is that in the Rust Belt states, those Whites without college degrees started at a much higher level. As a result, even after the decline, they remain about half the vote in most of the swing states there, rising to around 60% in both Wisconsin and Iowa. By contrast, they have now fallen below 40% of the vote in all of the key Sun Belt swing states, according to the census figures, and even dipped below 30% in Texas this year.

The final distinction is in the group filling the gap. In the Rust Belt states, the decline in blue-collar Whites has been offset primarily by an increase in the share of the vote cast by Whites holding at least four-year college degrees; the non-White share of the vote has increased slowly (by 4 percentage points or less) in all of those states except Pennsylvania.

But in most of the Sun Belt battlegrounds, those college-educated Whites are only maintaining their share of the electorate, while the minority population is growing much faster. In almost all the Sun Belt swing states, the minority share of the vote has increased by at least 8 percentage points since 2004, rising to about double that level in both Arizona and Nevada. (Colorado is the exception to that pattern, with college Whites and minorities both increasing their vote share about 5 to 6 percentage points since 2004.)

A trade of non-college for college-plus Whites in the electorate benefits Democrats, since they won a narrow majority of those well-educated voters last year, according to both the exit polls and the Catalist study. But Democrats benefit much more when non-college Whites are replaced by non-White voters, who usually back the party in proportions that range from 2-1 or 3-1, depending on the state. (Despite Trump’s significant improvement with Latinos, for instance, Biden still won two-thirds of voters of color in both Texas and Florida, the exit polls found.)

GOP reckoning coming in Sun Belt?

The electorate across the Sun Belt is virtually certain to continue diversifying at a rapid pace because kids of color constitute a majority (or near majority) of the young people turning 18, and becoming eligible to vote, in those states every year. Many analysts believe that demographic imperative explains the urgency and intensity of Republican efforts across the Sun Belt this year to pass laws making it more difficult to vote.

“In order for the Republicans to really prevent what’s coming down the road, unfortunately, they are positioning themselves to just roll it back to Jim Crow, basically,” in the laws governing access to the ballot, says McDonald.

In a similar spirit, Republicans now controlling Sun Belt state governments have responded to the rising population – and increasing Democratic tilt – of their largest metros by intensifying their efforts to override local decisions on a wide array of issues, particularly responses to the pandemic, in places such as Florida, Georgia, Arizona and above all Texas.

“It seems like all of the issues that help cities grow, and help them manage growth, have been ignored, and if anything the challenges have been exacerbated,” says Steven Pedigo, director of the LBJ Urban lab, of the state Legislature’s actions in Texas.

Population trends alone don’t determine a region’s political trajectory; what matters is the interplay between those changes and the way the parties position themselves, as well as regional differences in the political allegiance of the major groups. Though Democrats, for instance, advanced in urban Texas last November, the state still frustrated them because their performance there lagged their showings elsewhere not only among Whites (both those with and without college degrees) but also among Hispanics, especially in culturally conservative rural areas.

State laws that complicate registration and voting, and aggressive GOP gerrymanders, compound the likelihood that Democrats will face an arduous, and likely long, climb there. So long as the GOP can sustain the gains Trump registered last November with conservative Hispanics (mostly from Cuba or Central and South America), Florida looks very difficult for Democrats, too.

But if Democrats can consolidate their recent wins in Arizona and Georgia, and finally break through in both presidential and Senate races in North Carolina, a demographically similar state, they will still put enormous pressure on Republicans to reconsider their strategy.

Over two national elections, Trump has demonstrated that his bristling racial nationalism is a highly competitive message across the Rust Belt states crowded with the blue-collar and non-urban White voters most receptive to those arguments. But in the new Sun Belt battlegrounds, where the non-college White share has uniformly fallen to less than two-fifths of the vote and the non-White share of the population is rapidly growing, that messaging carries much greater long-term risks.

“There’s going to be a political and sociocultural reckoning in this decade where the Republicans are most likely going to have to say, ‘Our strategy of White nationalism doesn’t secure enough votes to sustain us as a national party,’ ” predicts Lang.

If that day ever comes for Republicans, the most likely scenario is that it won’t be triggered by reversals in the Rust Belt, but by further losses in the big Sun Belt battlegrounds moving toward center stage in the national competition between the parties.

CORRECTION: An earlier version of this article misattributed a comment by Democratic consultant Abhi Rahman.