Although a recent poll shows he trails in third place among candidates running for King County Executive, Dow Constantine is taking a risk that could bolster support from his lefty base or compromise his chances of making it to the general election. Holding a press conference at the Seattle Labor Temple Association building in Belltown this afternoon, Constantine thrust the record of frontrunner Susan Hutchison into the mainstream press. “She is … an extremely conservative Republican whose views are out of step with King County voters,” he said.

On one hand, Constantine demonstrates the frank confidence to say what other candidates, such as his fellow County Council Member Larry Phillips (another Democrat running for the seat vacated by Ron Sims), have been reticent to mention. But the move—which represents the sort of negative campaigning that voters tend to oppose—could be the political equivalent of Constantine of throwing himself on a grenade to ensure a Democrat wins the general election in November.

Under new rules, Hutchison isn't required disclose her party affiliation. Voters passed a measure in 2008 that made all King County races "nonpartisan"—meaning candidates can't list party affiliation in voters' guides or on ballots—the result of an initiative funded by and orchestrated by Republicans, including Hutchison. But, with cameras rolling and newspaper reporters taking notes, Constantine chronicled her support for far-right candidates and causes, and her attempt to hide that past.

Constantine noted that Hutchison, who is best known as a former anchor for KIRO television news, has served as a board member for creationist-theory-backing Discovery Institute, and she considered running for senate in 2005 as a Republican. (Erica Barnett goes into here.) She has also contributed over $10,000 to Republican candidates over the past four years, including Dave Reichert, Dino Rossi and George Bush. Indeed, her own campaign manager, Jordan McCarren, worked for a while on Mike Huckabee’s presidential campaign.

Partisan politics seemingly don’t apply to much of the county’s policies. But Constantine called state senator Karen Keiser (D-33) up to argue that Hutchinson could impact the county’s health department, which handles issues like providing abortion referrals to low-income women. “We need to know if elected leaders are in favor of women’s reproductive health,” she said. When it comes to other issues that progressives value—such as LGBT rights, and maintaining the urban growth boundary from spilling into natural areas—Hutchison has managed to hide her position from most voters.

“I think she is desperately trying to hide her partisan identity,” Constantine said.

Local voters, who vote overwhelmingly Democratic, have had little chance to hear Hutchison’s views, let alone challenge them or read about them in the press. Hutchinson has skipped every forum with other candidates, and she won’t attend a forum tomorrow hosted by anti-suburban-sprawl group Futurewise. “At forums, there is always that empty chair, “ he says. And the Seattle Times today reported that she has refused to schedule an interview with the newspaper since she announced her candidacy.

Constantine's lashings are necessary to expose Hutchison’s toxic GOP identity and disrupt her stealth campaign; no one else is doing it. He has support from several labor unions, and has historically been a more outspoken progressive than Phillips, so this step could draw attention to Constantine as a gutsy contender in the race and earn name recognition. But it could, on the other hand, set him up for a backlash from moderate voters, who typically resent nasty partisan politics. He contends he will make through it the primary election in August, and survive as one of the top two candidates to make the general-election ballot. But a KING TV poll released last Friday found that Constantine carried only eight percent of polled voters (behind Phillips's nine percent and Hutchison’s breakaway 34 percent). Phillips also has an advantage, having won the endorsement on Monday of the Alki Foundation, the political wing of the Greater Seattle Chamber of Commerce. While that endorsement might not mean much to voters, it could be a bellwether of future financial support from businesses for Phillips, which Constantine could lack. Regardless of how it plays out, however, Constantine is the only Democratic candidate among those running for county executive to come out swinging against their collective threat. He may be sacrificing himself to do it. “I don’t relish being the bad guy, but someone has to point out the truth,” Constantine said after the news conference.