WASHINGTON — Rep. Henry Waxman — a liberal ally of Speaker Nancy Pelosi — will take over the chairmanship of the powerful House Energy and Commerce Committee when the next Congress convenes in January.

Waxman is a liberal California Democrat. In an election among House Democrats, he toppled veteran Michigan Rep. John Dingell from the post. Dingell is the longest-serving member of the House.

Waxman won the panel chair by a 137-122 vote, capping a bitter fight within the Democratic Party caucus on the Hill.

Dingell has been the top Democrat on the panel for 28 years and is an old-school supporter of the auto industry. Waxman has complained that the committee has been too slow to address environmental issues like global warming.