Washington (CNN) -- A former Oregon state senator won the state's First Congressional District special election Tuesday night -- a victory that ensures a Democrat will continue to hold the House seat.
Suzanne Bonamici got 88,925 votes, finishing well ahead of Republican Rob Cornilles' 68,411 votes.
About 42% of registered voters cast a ballot in the special election conducted by mail only, a practice common in all Oregon elections.
The special election was called after former Rep. David Wu resigned over accusations of making unwanted sexual advances toward a fundraiser's daughter.
Though analysts expected the seat to stay with the Democrats, the race drew attention from the Democratic Congressional Campaign Committee and Emily's List, an organization that raises funds for female candidates.
In a relatively blue district, the committee painted Cornilles as a tea party supporter and ran an ad in which he brags about being "the original tea party candidate."
"Democrats successfully held the Republican accountable for his extreme tea party roots and his commitment to protecting the ultra wealthy at the expense of Medicare for seniors," Steve Israel, chairman of the Democratic Congressional Campaign Committee, said in a statement.
"This election is a win for middle class Oregon families who want someone to fight for them."
This was not Cornilles' first time running for the seat; the business consultant also challenged Wu in 2010.
Oregon's First Congressional District is a geographically diverse district that stretches from the state's largest city, Portland, to the rural Pacific coast. The district also includes the state's high-tech industry and Nike Inc. headquarters.
Though the district is geographically diverse, it has long been considered a Democratic stronghold -- as is much of Oregon. The first district has not sent a Republican to the House since 1975 and as of 2010, the state has almost 10% more Democrats than Republicans, according to the Oregon Secretary of State's office.
Additionally, President Barack Obama carried both the state and the district in 2008.