Only a couple of decades ago, Prince William County was one of the mostly white, far-flung suburbs where Republican candidates went to accumulate the votes to win elections in Virginia.
Since then, Prince William has transformed. Open acreages have given way to townhouses and gated developments, as the county -- about a half-hour south of Washington -- has risen to have the seventh-highest U.S. household income and become the first county in Virginia where minority members make up more than half the population.
If Prince William looks like the future of the country, Democrats have so far developed a much more successful strategy of appealing to that future. On Tuesday, President Obama beat Mitt Romney by almost 15 percentage points in Prince William, nearly doubling George W. Bush's margin over Al Gore in 2000, helping Obama to a surprisingly large victory in Virginia.
He did it not only by winning Hispanic voters, but also by winning strong majorities of the growing number of black voters and of voters younger than 40. A version of his coalition in Virginia -- a combination of minority members, women and younger adults -- also helped Obama win Colorado, Nevada and perhaps Florida, which remained too close to call. He came close in North Carolina, a reliable state for Republican presidential nominees only a few years ago that he narrowly won in 2008.
A demographic wall
The demographic changes in the U.S. electorate have come with striking speed and have left many Republicans, who have not won as many electoral votes as Obama did on Tuesday in 24 years, concerned about their future. The Republicans' so-called Southern strategy, of appealing mostly to white voters, appears to have run into a demographic wall.
"Before, we thought it was an important issue, improving demographically," said Al Cardenas, the chairman of the American Conservative Union. "Now, we know it's an essential issue. You have to ignore reality not to deal with this issue."
The central problem for Republicans is that the Democrats' biggest constituencies are growing. Asian-Americans, for example, made up 3 percent of the electorate, up from 2 percent in 2008, and went for Obama by about 47 percentage points. Republicans increasingly rely on older white voters. And contrary to conventional wisdom, voters do not necessarily grow more conservative as they age; until the last decade, a majority of both younger and older voters both tended to go to the winner of the presidential election.