The young man in the Oxford shirt and khakis stood in the doorway of the Manassas home with fliers in hand and introduced himself as a candidate for the House of Delegates.

"Really? You're running to be a state delegate?" a somewhat perplexed potential voter asked Steve H. Chapman, who flashed a boyish grin.

After explaining that he was indeed hoping to unseat Republican Del. Harry J. Parrish, 83, the author of the House plan to raise several taxes last year, Chapman bounded down the steps and went on to the next residence.

"I get that a lot," Chapman, 27, said, referring to the surprise people show when they find a twentysomething campaigning for a state office.

The GOP primaries in districts represented by six delegates who supported tax increases last year feature a wave of young, first-time candidates who are hoping to make an imprint on the General Assembly next year. Chapman is one of five young conservative challengers who are under 35 and running for seats represented by the GOP mavericks; of the five, three are younger than 30.

In each case, the young candidates have said that the GOP caucus needs to be infused with new ideas and that they can help keep lawmakers accountable to the Republican's conservative message.

"I felt as if the time to challenge was now," Chapman said. He is not only challenging Parrish's tax stand but also stances on gun control and social issues. "This district deserves someone who represents their values now . . . not later."

As the campaign was warming up in May, Chapman was charged in Prince William County with voting illegally last year and with election fraud for allegedly lying about where he lived in the fall. Those charges are pending. Chapman said he was innocent. Later, Chapman was served with a summons for letting his dog run loose in August 2004.

Parrish, who has represented the 50th District for 12 two-year terms, said all this was an example of the challenger not being ready for big-time politics.

Chapman said that the Parrish political machine stirred up the charges.

Parrish, who has spent more than 50 years in public service, said that the decision to support tax increases last year was a pragmatic one based on a firm understanding of what was right for the entire commonwealth, aside from the GOP's anti-tax orthodoxy.

He said he welcomed young candidates to the House, but that he was concerned that many of them had no local government experience.

Parrish said that if young challengers had a better understanding of what the tax package and the budget meant for cities and counties, they might have a better understanding as to why the plan was necessary.

"I'm a firm believer that anyone who goes to Richmond should have some form of local government experience," said Parrish, who served three decades as the mayor of Manassas. "Many times, those with no experience push for things when they don't realize what the impact is on local governments or on state government."

Political observers said that while elements of state and national politics always have been driven by the new ideas of younger, energetic political hopefuls, there appears to be a quickening of the pace in recent years.

"This is part of a broader trend that we've seen in the assembly and in politics in general . . . where [political campaigns] have become a much more entrepreneurial activity," said Robert D. Holsworth, the director of the Center for Public Policy at Virginia Commonwealth University.

He added that the emergence of younger candidates is a change from the days of political brokering, when established party leaders controlled who would run for state offices. He said in races such as the House primaries, where the odds are long and daunting, it's young people who often step up.

"Young people are far more willing to do the things it takes to run campaigns today," Holsworth said. "They're willing to knock on 4,000 doors, work 24-7 in a campaign. You can't minimize the importance of hard work in campaigns."

The challengers usually need to rely on that energy to counteract the incumbents' fundraising strength. Parrish, for example, had raised $293,652 as of June 1, compared with Chapman's $64,234, according to the state Board of Elections.

One delegate who was elected before the age of 30 said that the presence of young lawmakers was essential for the Republican legislative caucus to remain dynamic.

"The jury is still out on people who have 20 or 30 years experience," said Del. Jeffrey M. Frederick, 29, of Prince William County. Their experience "could be a positive as much as a negative," he said. Frederick defeated longtime Del. John A. "Jack" Rollison III in the 2003 GOP primary.

He said he was not talking specifically about any one delegate, but that in Richmond "there's a dominant attitude about 'this is how we've always done things and this is how we're going to continue to do things.' "

"That's really unfortunate because there are a lot of people who won't try stuff because they don't think it can go anywhere," Frederick said.

Holsworth said the stances that many younger candidates and delegates have taken against the more established delegates illustrate a subtle fault line in the majority party.

"You have one group that says they are really more in touch with the long-term needs of Virginia because they've had the experience . . . " Holsworth said. "On the other hand, you have a group that thinks that it's far more in touch with what the people really want."

Del. Harry J. Parrish, right, cites the lack of local government experience of his challenger, Steve H. Chapman.