California Rep. Henry Waxman built a reputation in the 110th Congress as a fierce watchdog, exercising his authority as chairman of the House Oversight and Government Reform Committee. In the 111th Congress, Waxman wants to be known as chairman of the House Energy and Commerce Committee.

Waxman today began campaigning for the prominent post, mounting a bid against incumbent chairman John Dingell of Michigan. Waxman, the second-ranking member of the committee, has a small cadre of early backers making phone calls to whip on his behalf. Tennessee Rep. Jim Cooper is one member who has called several members on behalf of the Californian.

But Dingell will be hard to unseat. The Michigan congressman, just elected to his 27th full term in Congress and the dean of the Democratic caucus, has served as chair or ranking member of the committee since 1981, becoming one of the most powerful members of Congress while irritating some environmentally-friendly Democrats with his fierce defense of the automobile industry.

A top Democratic leadership aide told Politics Nation that Waxman's decision to challenge his senior colleague caught party leaders by surprise. The leadership aide also said Waxman's challenge appears to be serious.