The Washington Post reports that Montana Sen. Max Baucus plans to retire rather than seek re-election in 2014. If true, this is big news on several fronts.

Baucus is chairman of the Senate Finance Committee and has been chairman or ranking minority member since January 2001, an unusually long tenure. Finance has a tradition of bipartisanship, and Baucus played a key role in securing passage of the Bush tax cuts in 2001 and the Medicare prescription drug bill in 2003. He also played a key role in Obamacare but just last week told HHS Secretary Kathleen Sebelius in a hearing that the law was heading for a “train wreck.”

The next in line Democrat on Finance is Jay Rockefeller of West Virginia, who has already announced he plans to retire. Next is Ron Wyden of Oregon, who has not always been a team player for the Obama Democrats; he joined with House Budget Committee Chairman Paul Ryan in supporting one version of Medicare reform, which would allow seniors to continue in the current Medicare program if they want to.

Who will succeed Baucus in the Senate if he retires? Montana voted 55 percent to 42 percent for Mitt Romney, but it has seldom elected Republican senators; the only one elected since 1946 has been Conrad Burns, who won in 1988, 1994 and 2000 but was defeated by Democrat Jon Tester in 2006. Against the state’s sole congressman, Denny Rehberg, Tester managed to win re-election by a 49 percent to 45 percent margin in 2012. Democrats have a strong possible nominee in former Gov. Brian Schweitzer, a folksy-talking populist who was elected in 2004 and 2008.

Baucus was first elected to the House in 1974 and to the Senate in 1978 at age 36. He has now spent half his life as a senator. Baucus staff alumni are well ensconced in lobbying positions in Washington and surely assumed that their former boss would run again at age 72; they must be disappointed if the Post story turns out to be true.