Both want to upset the incumbent and reclaim a seat that until four years ago was held by a Republican. Both are new to politics and have raised little money but think that Rep. Gerald E. Connolly (D-Va.) is vulnerable.

Yet there are enough differences between Chris Perkins, a retired Army colonel, and Ken Vaughn, a traffic engineer, to give Republican voters in the Fairfax County-based 11th Congressional District a clear choice in Tuesday’s primary.

The differences stretch from budget cuts to abortion to whether they should get together for a debate.

The winner will take on Connolly, who is running for a third term. Connolly beat businessman Keith Fimian (R) by less than 1,000 votes in 2010, but the district has been redrawn to be more favorable to Democrats. Connolly is also expected to benefit from having President Obama atop the ballot and from amassing a campaign war chest many times larger than that of either Republican candidate. Nationally, neither party puts the race in the top tier of competitive contests.

Turnout in the congressional primary is likely to be low, especially because the state held the primary for the Republican presidential nominee in March. “A lot of people do think there already was a primary,” Vaughn said.

Making the rounds

Knocking on doors in Oakton on a recent afternoon, Vaughn introduced himself to voters by saying that he is concerned about the federal debt.

“I always make clear that’s the reason I’m running — the debt,” Vaughn said. “That is a huge difference between us. I have a complete plan for how we get back to a reasonable, responsible budget.”

Making the rounds in a similarly upper-middle-class neighborhood in Lorton, Perkins began his pitch by noting that he is a retired military officer, which helps him connect with the district’s sizable population of veterans.

Perkins said federal spending was the number one issue, by a wide margin, among voters his campaign heard from, with jobs and the economy coming in second and national security issues third.

Both Perkins and Vaughn advocate spending cuts, but at a different pace.

“The basic message I’m trying to get at is we didn’t get here overnight,” Perkins said. “We’re not going to solve this problem overnight.”

Perkins contends that Vaughn’s proposed cuts are drastic and unrealistic. Vaughn counters that Perkins doesn’t support enough real cuts to fix the debt problem.

Like a small but growing number of Republicans across the country, neither Perkins nor Vaughn has signed the anti-tax pledge circulated by Grover Norquist’s group, Americans for Tax Reform.

“That doesn’t mean I’m not concerned about high taxes. I’m just more concerned about the debt,” Vaughn said.

Perkins said he declined to sign the pledge because “I do not believe I should sign away my ability to make hard calls.”

Vaughn’s campaign has tried to make an issue of abortion, sending out a mailer that says that Perkins is “pro-choice” and that Vaughn “supports passing a federal law that would define ‘personhood’ to include the unborn and protect them from abortion.”

Perkins defended his position, saying he is against “the use of taxpayer funding for abortion, but at the end of the day I believe it’s the woman who’s ultimately accountable, not Congress, and it’s up to her.”

Vaughn — who generally considers himself a libertarian at the federal level and a conservative at the state level — also has a somewhat complicated take on abortion.

Vaughn told The Washington Post this year that “I don’t think the Constitution is clear enough to say what the law should be at the national level.” And his campaign Web site says Congress “should pass a law that explicitly states that personhood shall be deemed to begin based on the laws within the local state, with a default beginning point when no such law is provided.”

No debates

Perkins has refused to debate Vaughn, saying it would be “divisive” and won’t help either man in the long run. But Vaughn contends that debates would have given the congressional race some much-needed public attention.

“Neither of us has the name recognition to go in and beat Connolly, so it’s a bad strategy regardless,” Vaughn said.

Vaughn and Perkins lack name recognition and another key campaign ingredient: cash.

Perkins raised just $13,000 from April 1 through May 23, and he had $60,000 in the bank as of the latter date. Vaughn raised $29,000 over the same period and had $32,000 on hand. (Connolly has a $1 million war chest.)

Perkins has not run any radio or television ads. “Quite frankly, I couldn’t afford it,” he said.

And he said he “made a conscious decision” not to do much fundraising in the run-up to the primary and to focus on retail politics instead, on the advice of former congressman Tom Davis, who held the seat for 14 years and endorsed Perkins last month.

Vaughn also decided against advertising in the primary. He said the “personal touch” was the best way to win support.

In Oakton, that appeared that might be the case.

Dorsey Wittig, a semiretired IT consultant, said he would back Vaughn simply because “he came to my home and asked for my vote.”