U.S. Senate Photographic Studio · Public domain

Oregon's senator since 1996 and previously its congressman for fifteen years, he has combined a Democrat's policy priorities with a libertarian's suspicion of government power, making him one of the Senate's most consistent advocates for privacy rights and against mass surveillance, including sustained opposition to bulk data-collection programs revealed in 2013. He serves as ranking member of the Senate Finance Committee and is the dean of Oregon's congressional delegation.