When author and Washington Post reporter Joel Garreau coined the term ‘‘edge city’’ to describe the autonomous urban centers developing on the rims of some of the nation’s largest metropolitan areas, his prime example was Tysons Corner, Va. Rising on a hill west of Washington, D.C., Tysons Corner was a back-country intersection 50 years ago. By the late 1980s, it was the largest concentration of office space to be found anywhere between Washington and Atlanta, with a modern skyline and busy multi-lane avenues that served as arteries to the Capital Beltway. Fairfax County, which includes Tysons Corner, had been a typical postwar suburb. It had only 99,000 people in 1950, far fewer than Washington’s 802,000, and less than the 197,000 people who lived in closer-in Arlington and Alexandria. But in the years that followed, the trickle moving into Fairfax became a gusher. In 2000, it had 991,000 people, nearly twice D.C.’s. 572,000 and three times the 318,000 population of Arlington and Alexandria. They were mostly affluent people. Fairfax County in 2000 had the highest median household income of any county over 250,000 population, with dazzlingly high percentages of residents with college degrees and two or more cars.

In the last decade, Fairfax County has changed. Just as Tysons Corner made it a major commercial center, so it has taken on other characteristics traditionally associated with a central city. Population growth has been slow since 2000; the county passed the 1 million mark in 2002 and stopped for the most part. Meanwhile, suburban Loudoun County vaulted ahead of Fairfax in median household income, and Prince William County has been growing at a fast clip, attracting the young families that Fairfax once did. Some communities have remained unchanged, like Clifton, which still resembles a quaint old Virginia village. But much has changed. Immigrants—Koreans and Vietnamese, Ethiopians and Afghans, Salvadorans and Mexicans–have put their stamp what once were mostly white, heavily Protestant neighborhoods.

The recession hit Fairfax with less force than much of America. Unemployment rose in 2008, but remained well below national levels. The federal government still provides a solid base for the local economy and the Federal Transportation Administration in August 2008 approved the nearly $5.2 billion extension of the Washington-area Metrorail system from Tysons Corner to Dulles Airport. Unlike Loudoun and Prince William counties, Fairfax has declined to pass ordinances denying services to illegal immigrants, but as construction and service jobs vanish, there is evidence of immigrant outflow from the area.

The 11th Congressional District of Virginia consists of much of Fairfax County and most of Prince William County. It straddles the Capital Beltway and includes Tysons Corner. Inside the Beltway is Annandale; beyond are Vienna, Fairfax, much of Springfield, Burke, Clifton, Centreville and part of Mount Vernon. In Prince William County, it includes Woodbridge and Dale City, areas with large Latino immigrant populations, and stretches west to Haymarket. This is a cosmopolitan district: it is 11% African-American, 14% Hispanic, and 14% Asian. Demographic change has produced political change. Immigrants have been voting more Democratic than the people they have replaced, and among non-immigrants, liberal attitudes on cultural issues moved voters against President George W. Bush and his Republicans and toward Democrats like Gov. Tim Kaine and Senators Jim Webb and Mark Warner. In recent presidential contests, the district voted 52%-45% for Bush in 2000 but only 50%-49% for him in 2004 and 57%-42% for Democratic nominee Barack Obama in 2008. The seat also fell into Democratic hands in the congressional election that year.