President Barack Obama's election victory exposed tectonic demographic shifts in American society that are reordering the U.S. political landscape.

The 2012 presidential election likely will be remembered as marking the end of long-standing coalitions, as voters regroup in cultural, ethnic and economic patterns that challenge both parties—but especially Republicans.

Older voters and white working-class voters, once core elements of the Democratic Party, have drifted into the Republican column. Rural and small-town voters, whose grandparents backed the New Deal, now fill the swath of the U.S. that leans reliably GOP.

But in cities and dynamic suburbs, a rapidly growing force of Latinos, Asian-Americans, African-Americans and higher-income whites emerged this week as the strength of Mr. Obama's winning Democratic coalition.

"The Democrats now own a coalition of emerging metro areas where the whites and minorities live together, and where they vote Democratic," said Robert Lang, a demographer who directs the Brookings Mountain West, a research center at the University of Nevada, Las Vegas.