Md., Va. Challengers' Fate May Depend on Inner Suburbs' Muscle

"It does seem to me something that Montgomery County will be recognized for when the dust settles," state Sen. Brian E. Frosh (D) said of Leggett's "remarkable triumph." "What it says about Montgomery County is that we're pretty colorblind."

Across the Potomac, the influence of Northern Virginia -- where about 30 percent of the state's voters reside -- is debated annually because of the commonwealth's uncommon political calendar.

In 2004, as Rozell pointed out, Democratic presidential nominee John F. Kerry showed that it was possible to win Northern Virginia and still lose the state. The next year, Timothy M. Kaine expanded Democratic gains into Loudoun and Prince William counties and combined support in other suburban areas to win the governorship by an even larger margin than fellow Democrat Mark R. Warner had seen four years earlier.

This year, polls consistently show strong support in the region for Webb -- and a growing distance from attitudes in the rest of the state.

In a Washington Post poll conducted last month, Webb led Allen 56 percent to 42 percent in Northern Virginia, defined as Alexandria and Arlington, Fairfax, Fauquier, Loudoun, Prince William and Stafford counties and all the cities contained within. Allen led by 10 points elsewhere in the state.

On a host of issues -- including President Bush's popularity, support for the war in Iraq and amending the state constitution to prohibit same-sex marriage -- there were wide disparities between the region and the rest of the state.

Those differences are likely to grow, demographers and political scientists say, and so is the area's influence.

"I think gone are the days when candidates can count on winning without winning Northern Virginia," Rozell said.

Robert E. Lang, director of the Metropolitan Institute at Virginia Tech, said future statewide politicians will need to rethink how to fashion their campaigns.

"The first order of business is going to be, 'What are you going to do about Northern Virginia, how are you going to take care of those people?' " Lang said. "Because they're active, they're energetic, they vote, they're booming."

Robert D. Holsworth, director of the Center for Public Policy at Virginia Commonwealth University, said the region's changing politics threatens Allen and future GOP candidates. He called it a dilemma for the "tried-and-true way of trying to win a Republican campaign."

Allen's top consultant, Chris LaCivita, conceded that Northern Virginia has become a challenge.

"Clearly, it's tougher than it used to be," said LaCivita, who has run campaigns in Virginia for years and once directed the state's Republican Party. But LaCivita said that Allen has not given up on the area and believes that some of the most potent GOP messages can be tailored to be just as effective there as in other parts of the state.

"Northern Virginians have more to lose as it relates to taxation," he said. "It's bad enough that federal taxes are too high. But when the localities come on top of it, those are issues that have a particular resonance up here in Northern Virginia."

Lang agreed that new residents of what he calls the "new quasi-urban space of Northern Virginia" are not particularly liberal or even Democratic. "It's a moderate politics," he said, but with its large foreign-born population and growing number of single people, "it's becoming more like the North than the South."

By the middle of the next decade, Lang said, Virginia might more resemble Illinois -- with its urban upstate, rural downstate split -- than fellow Southern states. Lang said that if Allen survives this election, he might return to his Southern California roots for a campaign persona.

"The Southern California Allen would do better in 2012 than the cowboy one," Lang said.

Staff writers Matthew Mosk and Michael D. Shear and researcher Meg Smith contributed to this report.