Sen. Max Baucus announces retirement plans WASHINGTON -- In a surprise move that deals a serious blow to Democratic chances of holding the Senate, veteran Montana Sen. Max Baucus has decided not to seek reelection next year, Democratic officials said Tuesday. Baucus chairs the Senate Finance Committee and was expected to be a major player in the coming debate over reforming the nation's tax system. A Democratic aide said that Baucus" decision could complicate the tax-overhaul effort and that there might be calls for the lame-duck senator to relinquish his chairmanship before his retirement takes effect. The Montanan's decision, first reported by the Washington Post, appeared to take the White House and other Democratic leaders by surprise. Baucus was among four Democrats who opposed last week's gun control measure, three of whom were facing reelection in 2014 A liberal Democratic group which had already begun an effort to oppose Baucus's reelection hailed his decision as a victory. Good bye, Senator K Street. Max Baucus has a history of voting with corporate interests and not the interests of Montana voters -- taking millions from Wall Street, insurance companies, and lobbyists," Stephanie Taylor, co-founder of the Progressive Change Campaign Committee, said in a statement. Montana will finally have a chance to have a senator with its best interests at heart, and we hope Brian Schweitzer jumps into the race immediately, But Baucus" decision puts in serious jeopardy one of the seats that Republicans considered a prime pickup target in 2014. Montana's former Democratic governor, Brian Schweitzer, who had been toying with a long shot 2016 presidential try, is now leaning toward running for Baucus" seat, according to a Democrat familiar with the former governor's thinking. Baucus is the sixth incumbent Democratic senator to announce his retirement ahead of next year's election and the fourth whose retirement puts a seat up for grabs in a Republican or tossup state. The others are Sens. Jay Rockefeller of West Virginia, Tim Johnson of South Dakota and Tom Harkin of Iowa. Six other seats currently held by Democrats are also at risk next year - in Alaska, Arkansas, Louisiana, Minnesota, North Carolina and Michigan. None of the Republican seats at stake in next year's election appears to be seriously vulnerable. Democrats currently hold a 55-45 majority in the Senate, and the GOP would need a net pickup of six to take control of the chamber. Republicans are already favored to maintain their House majority in 2014.