Not only do Detroit's Big Three appear to be on the verge of going down, but their biggest defender, 81-year-old Rep. John Dingell, D-Mich., may be about to lose his powerful post as the chairman of the House Energy and Commerce Committee. The Wall Street Journal is reporting that California's Henry Waxman won a Democratic Steering Committee vote to take over the chairmanship.

It's not a done deal yet; the full House Democratic Caucus will vote yea or nay on the decision on Thursday. But if the rank-and-file membership upholds the Steering Committee vote, you can expect environmentalists to be doing some more dancing in the street. Many activists consider Dingell to have been a steadfast opponent of tougher fuel economy standards. His 2007 proposal to tax carbon emissions was widely viewed as a sneaky political maneuver aimed at equating climate change action with big new taxes. Waxman, on the other hand, favors an aggressive approach to tackling climate change and other environmental issues.

On Tuesday, Barack Obama reiterated his support of a federal cap-and-trade system for limiting greenhouse gas emissions, in a video message sent to a California global warming summit. It will be a lot easier to get such legislation through the House if Waxman is calling the shots, instead of Dingell.