Polling, consumer data and demographic profiles paint a picture of two Americas—not just with differing proclivities but different life experiences. People in cities are more likely to be tethered to a smartphone, buy a foreign-made car and read a fashion magazine. Those in small towns are more likely to go to church, own a gun, support the military and value community ties.
In many ways, the split between red Republican regions and blue Democratic ones—and their opposing views about the role of government—is an extension of the cultural divide between rural Americans and those living in cities and suburbs.
As Democrats have come to dominate U.S. cities, it is Republican strength in rural areas that allows the party to hold control of the House and remain competitive in presidential elections.
"The difference in this country is not red versus blue," said Neil Levesque, director of the New Hampshire Institute of Politics at Saint Anselm College. "It's urban versus rural."
The U.S. divide wasn't always this stark. For decades, rural America was part of the Democratic base, and as recently as 1993, just over half of rural Americans were represented by a House Democrat, according to a Wall Street Journal analysis. Conservative Democrats often represented rural districts, including [Rep. Vicky] Hartzler's predecessor, Ike Skelton, who held the seat for 34 years before she ousted him in 2010.
That parity eventually gave way to GOP dominance. In 2013, 77% of rural Americans were represented by a House Republican. But in urban areas—which by the government's definition includes both cities and suburbs—slightly less than half of residents were represented by congressional Republicans, despite the GOP's 30-seat majority in the House.
The urban-rural divide has also grown in presidential contests. In 1992, Democrat Bill Clinton beat Republican George Bush in the 50 densest counties—the most urban in the country—by 25 percentage points. By 2012, Democrat Barack Obama's advantage in those urban counties had shot up to 38 points, according to a Journal analysis of Census and election data.
Today, almost all big cities, even those in red states such as Missouri, Indiana and Texas, favor Democrats for president.
The shift in rural areas has been even more dramatic. In 1992, Mr. Bush won the 50 least-dense counties—the most rural in the country—by 18 points. In 2012, Mr. Romney's advantage there had roughly tripled, to 53 points.Much of the change reflects the realignment of the rural South from Democrat to Republican.