It's official:

California Rep. Henry A. Waxman on Thursday officially dethroned longtime Energy and Commerce Chairman John Dingell, upending a seniority system that has governed Democratic politics in the House for decades.

In a secret ballot vote in the Cannon Caucus Room, House Democrats ratified an earlier decision by the Steering and Policy Committee to replace the 82-year-old Dingell with his 69-year-old rival. The vote was 137-122 in favor of Waxman.

The ascension of Waxman, a wily environmentalist, recasts a committee that Dingell has chaired since 1981 with an eye toward protecting the domestic auto industry in his native Michigan. The Energy and Commerce Committee has principal jurisdiction over many of President-elect Barack Obama's top legislative priorities, including energy, the environment and health care.

As John says, this is truly welcome news. We may finally get some oversight from this committee. Matt Stoller has more.