Updated: 7:43 p.m.

Republican John Koster is declaring a victory of sorts in Washington’s 2nd district nonpartisan primary.

Democratic Rep. Rick Larsen finished slightly ahead on the night of last week’s contest, but the counting of outstanding ballots since has pushed Koster to a 316-vote lead.

Koster and Larsen faced three other contenders in the primary, which advances the two best finishing candidates to the general election regardless of their party affiliation. While there technically is no winner, Koster said it’s a bad sign for the five-term incumbent he will now face in the general election.

“There’s no way he’s going to catch up,” Koster said in a phone interview.

And Koster’s spokesman, Matt Parker, added, “There is no better poll than one with a sample size of 170,000.”

There are six counties in the district, including a small slice of Seattle’s King County. The other five counties have a total of 197 ballots remaining to be counted. King County has 2,000 uncounted ballots, but only a few are likely to be from within the 2nd district.

To give an idea of how few 2nd district voters are in King County, only 147 votes were counted so far with all of the county’s 2nd district precincts reporting.

Larsen political director Brooke Davis wrote in an e-mail, “Voters have a choice this fall: join Rick Larsen as he works to move our country forward and helps to build an environment where businesses can create jobs and thrive, or join John Koster who wants to return to the failed policies that led to the recession.”

With the Democratic lean of the district and its being a two-person race from now on, the general will be more difficult for Koster. The Northwest Washington district voted 56 percent for President Barack Obama in 2008, and in 2004 gave Sen. John Kerry a slimmer 51 percent win in the presidential election.

But Koster said that for many reasons, this year is unique.

“The difference is what’s happened over the last couple years: huge deficits, rising unemployment, the votes Rick’s taken along with Nancy Pelosi, the out-of-control spending,” Koster said. “The other part is that the candidates in the past were not able to get any traction.”

That includes Koster himself, who ran against Larsen when the Congressman was first elected in 2000. Koster, then in the state legislature, won the all-party primary that year as well, 49 percent to 46 percent, but he went on to lose to Larsen, 50 percent to 46 percent, in the general election.

Larsen outspent Koster that year by more than $500,000. Through July this year, Larsen held a cash advantage of more than $700,000.

Still, the overall political mood may favor Republicans, and GOP Senate nominee Dino Rossi is in contention with Democratic Sen. Patty Murray — a factor that could help drive turnout on the GOP side.

“We have a great grass-roots campaign to this point, and we’ll get up on TV if we can,” said Koster. “The wind is at our back.”