Asked by The Hill why the group would pick a fight with Lingle, a centrist Republican woman who has supported abortion rights in the past, Schriock said those factors weren't enough.
"Our mission is to support pro-choice, Democratic women, and it is three of three for a reason," she said.
In another Senate race in Connecticut, the group has backed former Connecticut Secretary of State Susan Bysiewicz (D), putting it at odds with the Democratic Senatorial Campaign Committee, which has thrown its support behind Rep. Chris Murphy (D-Conn.).
"Connecticut voters are going to vote for a Democrat against [GOP front-runner] Linda McMahon in November, and EMILY's List is going to do everything we can to make sure that Democrat is Susan Bysiewicz," Schriock said.
The group unveiled a video montage Thursday of big-name Democrats declaring their support for the group, including former President Clinton, Sen. Kirsten Gillibrand (N.Y.), Labor Secretary Hilda Solis and Health and Human Services Secretary Kathleen Sebelius.
The PAC also released the results of a poll it commissioned in Oregon on Tuesday, the day Bonamici was elected, showing that female voters list the economy, protecting entitlements and tax fairness as their top three election issues.
Almost 80 percent of those who supported Bonamici said her Republican rival's opposition to abortion rights was a factor in their decision.
— This story was updated at 3:06 p.m.