The Montana Democratic senator is involved in a high-stakes 2012 race, one of a few that could shift the balance of power in the Senate.
Sharla Tester and husband, Sen. Jon Tester (D-Mont.), move organic peas as fertilizer for their wheat farm in Big Sandy, Mont., on April 22, 2011. In his bid for reelection, Tester faces a formidable challenge from Republican Rep. Denny Rehberg, Montana’s sole congressman, who has won election statewide six times. Philip Rucker/The Washington Post Buy Photo