Wow, Henry Waxman actually managed to dislodge John Dingell from his perch atop the House energy and commerce committee. The full Democratic caucus approved the change this morning on a 137-122 vote. Dingell had seniority and, befitting a guy who's been toiling and backslapping in Congress since 1955, considerable sway in the chamber, so it was always outlandish to think that anyone could challenge him for the chairmanship—let alone win. Waxman no doubt benefitted from his close relationship with Nancy Pelosi, who has lately been skirmishing with Dingell over fuel-economy standards and climate legislation (she even set up a new select committee on global warming in 2006 to try to circumvent him). But the leadership largely stayed aloof from this particular feud.

It appears Waxman won, in part, because Democrats are increasingly focused on global warming and think now's the time to act, to make a decisive break with the do-nothing Bush years. Barack Obama just reiterated his intent to pursue a nationwide cap on greenhouse-gas emissions. In the Senate, both Jeff Bingaman and Barbara Boxer want to move forward. That just left the House, where, according to his critics, Dingell had been dragging his feet on the issue. His recent climate bill was attacked by many enviros—including one of Obama's top EPA transition officials—for being too flimsy and loophole-ridden. Dingell's caution was understandable: He represents Dearborn and the auto industry, and even though he's a genuine liberal who's done a lot of utterly indispensible environmental work (authoring the Endangered Species Act and Clean Water Act, for one), it's hard to support robust action on carbon while simultaneously sticking up for the more parochial interests of Ford, GM, and Chrysler.

Waxman has fewer constraints in that arena, and generally supports a much more aggressive stance toward climate change and curbing greenhouse-gas emissions. His own cap-and-trade bill is certainly ambitious, with far stricter targets than the Lieberman-Warner bill debated in the Senate over the summer, and he's even called for moratorium on new coal-fired plants that can't sequester their emissions. On environmental issues, at least, this is a massive policy shift, and one that a majority of House Democrats just endorsed. Whether Waxman can actually make these things happen remains to be seen.

--Bradford Plumer