Two Republican candidates for the House of Delegates served with distinction in Vietnam and gave up higher paying work to serve in public office. But that's about all Richard H. Black and David G. McWatters have in common.

The two candidates seeking the GOP nomination for the 32nd House District, which includes part of Loudoun County and a sliver of Fairfax County, represent opposite wings of the Republican Party.

Black, the incumbent who took office after a special election last year, is among the most conservative members of the General Assembly, advocating antiabortion license plates and additional restrictions on abortion and Internet pornography. McWatters, a Loudoun County supervisor from the Broad Run district, is more moderate and has pushed regularly for more funding for schools, even if doing so required increasing taxes.

They portray one another as extreme, and some political analysts said the race could be a bellwether of the future of Republican politics in Northern Virginia. The primary is Tuesday.

"He's the poster child for the extreme right wing," McWatters said.

"There's no doubt that McWatters would be one of perhaps three of the most liberal Republican members of the House of Delegates were he elected," said Black, 55, of Sterling.

The winner of the GOP primary will face Democrat Kelly Burk in November. Burk, president of the Loudoun Education Association, faces no opposition in the primary.

McWatters, a Realtor, has served 3 1/2 years on the Loudoun Board of Supervisors. He has lived in the 32nd District for 21 years. Black, a lawyer, won a special election in February 1998 after then-Del. William C. Mims (R-Loudoun) won election to the state Senate. He has lived in the 32nd District for 3 1/2 years.

McWatters, 57, of Sterling, is running on a platform that calls for more tax dollars to be returned to localities to pay for schools. He wants more money for teacher salaries and transportation projects.

He also said the General Assembly needs to do more to help suburbs battle sprawl. As a supervisor, he endorsed a measure that would have allowed localities to cut off development in areas where there are not enough roads or schools; that measure, along with a number of other growth control bills, failed in the General Assembly.

Last week, Black began campaigning on a slow-growth theme, branding his opponent "Sprawl McWatters" in advertising. Black criticized McWatters for failing to support fees for developers on every new house they build; McWatters said he opposes such measures because they add to the cost of housing and price middle-class people like sheriff's deputies and teachers out of the market. Black also criticized McWatters for supporting a county policy that allows some residential developers to build to a higher density if they include low-cost housing.

McWatters has the backing of a Loudoun group called Voters to Stop Sprawl, which said McWatters has a better record on the issue.

Black, endorsed by Gov. James S. Gilmore III (R), said he wants to continue to focus on "family values" issues in the General Assembly.

Black has been a controversial figure in the legislature because of his efforts against abortion and pornography and for a proposal to make it legal to carry concealed weapons in restaurants and bars that serve alcohol. Black also said he wants to continue working on transportation issues and to look for regional solutions to gridlock.

When Black served on the Loudoun library board before taking office, he helped craft a policy that required the use of filtering software on computers with Internet access as a way of preventing patrons from looking at pornography.

The policy was ruled unconstitutional by a U.S. District Court judge, and despite Black's call for an appeal, the current library board has altered the policy. After his election, Black unsuccessfully proposed legislation that would have required filters on public school computers.

"I have done everything that I could conceivable do to keep vice and corruption out of the county--particularly through the battle with the Internet," Black said. "I've got an opponent who mocks opponents of pornography, who denigrates their efforts. He clearly is on the other side."

McWatters said he wants to keep pornography out of libraries, but he said requiring adults to use the filtering software could violate free-speech rights. He said that Black has become "obsessed" with the issue and that he should spend his time addressing concerns of greater significance to constituents. He also criticized Black for taking a television reporter into a Loudoun library and pulling up Web pages Black said contained "gruesome" images of rape victims.

"We never ever in the history of this county ever had people go to the library and pull [up] pornography on the screen," McWatters said. "Now we've got one."

Black said he did it to show what kinds of Web pages children could view.

CAPTION: Richard H. Black is a conservative.

CAPTION: David G. McWatters is a moderate.