Washington (CNN) - Washington Sen. Patty Murray accepted the chairmanship of the Democratic Senatorial Campaign Committee Tuesday morning, two sources confirm to CNN.
"She was pushed," a source close to Murray told CNN. "It certainly wasn't something she had any plan for election day."
Thirty-three Senate seats are up for grabs in 2012, with 23 of those belonging to Democrats and the two independents who caucus with them.
It's doubtful that the political climate will be as friendly in 2012 to Democrats as it was in 2006, when the party won back control of both the House and the Senate. Among those Democratic senators who could face challenging re-elections: Sherrod Brown of Ohio, Jim Webb of Virginia, Ben Nelson of Nebraska, Claire McKaskill of Missouri, Jon Tester of Montana, Kent Conrad of North Dakota, Bill Nelson of Florida, and Joe Manchin of West Virginia.
–CNN Deputy Political Director Paul Steinhauser contributed to this report.
(Updated at 12:29 p.m. ET)