sentences:  Then, in a major upset, he defeated 20-year incumbent, Republican Don Clausen by just over two points.In Congress, Mr. Bosco, an advocate of fishery and natural resource conservation, authored the California Wilderness Act, the Smith River National Recreation Area Act.And in 1989, along with Barbara Boxer and Nancy Pelosi, Mr. Bosco co-authored the legislation to preserve the Cordell Bank National Marine Sanctuary, protecting the coast of northern California from offshore oil drilling.