WASHINGTON — America's population center is edging away from the Midwest, pulled by growth in the Southwest, according to census figures. The historic shift is changing the nation's politics and even the traditional notion of the country's heartland — long the symbol of mainstream American beliefs and culture.
The West is now home to the four fastest-growing states — Nevada, Arizona, Utah and Idaho — and has surpassed the Midwest in population, according to 2010 figures. California and Texas added to the southwestern population tilt, making up more than one-fourth of the nation's total gains since 2000.
When the Census Bureau announces a new mean center of population next month, geographers believe it will be placed in or around Texas County, Mo., southwest of the present location in Phelps County, Mo. That would put it on a path to leave the region by midcentury.
"The geography is clearly shifting, with the West beginning to emerge as America's new heartland," said Robert Lang, a sociology professor at the University of Nevada-Las Vegas who regularly crunches data to determine the nation's center. "It's a pace-setting region that is dominant in population growth but also as a swing point in American politics."
The last time the U.S. center fell outside the Midwest was 1850, in the eastern territory now known as West Virginia. Its later move to the Midwest bolstered the region as the nation's cultural heartland in the 20th century, central to U.S. farming and Rust Belt manufacturing sites.
In the 1960s, "Will it play in Peoria?" was a common phrase that coincided with the U.S. center's location in Illinois. It was a measure of whether a politician or consumer product could appeal to mainstream Americans with traits associated with Midwesterners, such as stability and caution.
But over the last decade, the Phoenix suburb of Peoria, Ariz., soared past its Illinois namesake in population. Democrat Barack Obama in 2008 successfully made the Republican-leaning Mountain West a key component to winning elections, with Colorado, Nevada and New Mexico now considered swing states.
With Arizona on track to surpass Ohio in electoral votes by midcentury, based on projected growth, issues important to the West, such as Arizona's sharp debate over immigration, gain in political significance.
The Census Bureau calculates the mean U.S. center every 10 years based on its national head count. The center represents the middle point of the nation's population distribution — the geographic point at which the country would balance if each of its 308.7 million residents weighed the same.
The latest 2010 figures show a loss of House seats for states including Missouri and some of those east of it, primarily in the declining Rust Belt. Eight of the 12 pickups in House seats occurred in states west of Missouri, with Florida (with two new seats), Georgia and South Carolina in the Southeast being the exceptions.
The fastest U.S. growth is occurring in the Mountain West, which includes Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah and Wyoming. As California's growth slows, many of the Mountain state arrivals are Hispanic immigrants seeking jobs and affordable family living. Hispanics tend to lean Democratic when voting.
* In Arizona, which gains a House seat, Hispanics accounted for roughly half of the state's population increase since 2000, according to census estimates. Arizona has picked up at least one House seat every decade since 1950; its total seats could outnumber Ohio's as early as 2040 — so long as anti-immigration sentiment and recent mortgage foreclosures don't curtail its long-term growth.
* In seven of the eight Mountain states, Hispanics accounted for nearly 50 percent or more of the population gains among children under 18. Montana, which had a population loss of children, was the exception.
* The Western U.S. grew 13.8 percent from 2000 to 71.9 million people, surpassing the Midwest as the second most populous region. The Midwest rose 3.9 percent and the Northeast gained 3.2 percent. The West's growth rate is nearly equal to the South's, which rose 14.3 percent to 114.6 million on the Sun Belt strength of Texas and Florida.