Former Oregon state Sen. Suzanne BonamiciSuzanne Marie BonamiciCongress — when considering women’s health, don’t forget about lung cancer Overnight Energy: Two top Pruitt aides resign at EPA | 17 states sue EPA over car emissions rules | Volkswagen to pay West Virginia .5M over emissions cheating House Dems question Pruitt over possible plans for Tulsa EPA office MORE (D) emerged the victor of a special House race in Oregon on Tuesday, besting Republican businessman Rob Cornilles after months of expensive and intensely negative campaigning by both candidates.

With 69 percent of the vote counted, Bonamici led Cornilles 54 percent to 39.

In a speech to supporters, Bonamici said she was "humbled by this awesome responsibility" and pledged to work in Washington to boost job growth in Oregon and the country.

In his concession speech, Cornilles sounded a defensive note after a bruising campaign fight. "Voters got a different story about the work that I do," he said about attacks from the Bonamici campaign on his business record. 

Cornilles also pointed to the money pro-Bonamici groups poured into the race as contributing to his loss. "It's tough to compete with that, and that's unfortunate," he added.

Bonamici and Cornilles had been campaigning for the seat that has sat vacant since Rep. David Wu (D-Ore.) resigned in July amid a sex scandal. Wu was accused of a sexual relationship with the teenage daughter of one of his donors.

The election was conducted entirely through mail-in ballots, and attracted heavy attention from the national parties and members of Congress from around the country.

With nationwide elections for all House districts less than a year out, both parties were aware that the results of the Oregon race would be dissected by political handicappers, and seized by the winning party as a harbinger of their success in November. Democrats need to flip 25 Republican-held districts to take back control of the House, and have sought to portray GOP lawmakers as obstructionist to win over voters.

In a statement, House Minority Leader Nancy Pelosi (D-Calif.) said the victory was a "clear message from Oregon voters that they want their elected officials to create jobs and stand up for small business, while standing strong against Republican efforts to end the Medicare guarantee."

She praised Bonamici as "an independent voice for growing our economy and bolstering our middle class.

Democrats started out with an inherent advantage in this left-leaning district in the Portland, Ore., area, where Obama beat Sen. John McCainJohn Sidney McCainTo woo black voters in Georgia, Dems need to change their course of action Senate panel again looks to force Trump’s hand on cyber warfare strategy Senate panel advances 6B defense policy bill MORE (R-Ariz.) 61-36 four years ago. But that advantage also worked to raise the expectations that Bonamici would win by a wide margin.

But Bonamici found herself bloodied by stinging attacks from Cornilles, responding in turn with a similar level of rancor.

Cornilles claimed that Bonamici, a former Federal Trade Commission attorney, had zero experience in creating jobs, and painted her as an extreme liberal ideologue. In the waning days of the campaign, he also tried to tie her to Wu, alleging she and her husband, who worked for Wu, had tried to cover up his misdeeds.

Bonamici struck back by going directly after Cornilles's perceived strength: his record as a businessman. Her campaign ran ads informing voters that his sports marketing business had been hit with a federal tax lien, and argued his claims to have created thousands of jobs were grossly exaggerated.

Both Cornilles and Bonamici vowed that their chief responsibility if elected to federal office would be to produce jobs in Oregon and elsewhere. 

Both candidates also tried to force the other into a corner on Medicare, escalating the issue to a central theme of the special election.

Still stinging from a defeat in two special House races in September, Democrats weren't willing to take any chances in Oregon. The Democratic Congressional Campaign Committee (DCCC) poured well over $1 million into ads in the race, according to a Republican source tracking ad buys. And Bonamici was also bolstered by support from other Democrat-aligned groups such as EMILY's List, a political action committee that supports female candidates who favor abortion rights.

The heavy spending by the DCCC led Cornilles and his allies to claim that Democrats were trembling in their boots. But Democrats maintained they were playing it safe and simply taking nothing for granted.

House Republicans made a last-minute investment of less than $85,000 in Cornilles's candidacy, but not enough to seriously contest the influx of funds from Democratic groups.