Montana Sen. Max Baucus, one of the most influential congressional figures of his era, announced his intention Tuesday to retire, a move that could produce sweeping changes in the political and legislative landscape over the next two years.

The announcement could mark the beginning of one of the most consequential periods in Baucus' long public career, because he pledged to devote the rest of his time in Washington to pursuing a comprehensive rewrite of the federal tax code, an effort that many see as key to breaking the fiscal gridlock that has paralyzed Washington in recent years.

That paralysis of taxes and spending has been a central feature of Barack Obama's presidency, and Baucus, 71, said that when the president called him Tuesday about his retirement, the talk quickly turned to tax reform. "They're going to get tired of me," Baucus said in an interview, adding that White House officials do not "know themselves where they are" on a strategy for ending the stalemate.