There is usually reason to celebrate when the US House’s tradition-bound seniority system is upset, and such is the case — with a few cautions and codicils — with the determination of the House Democratic Caucus to put California Congressman Henry Waxman in charge of the chamber’s exceptionally powerful Energy and Commerce Committee.

In a showdown of the sort rarely seen in recent decades, the caucus voted Thursday morning to remove the current chair and long-time definitional player on the committee, Michigan Congressman John Dingell. The vote was close – 137 for Waxman, 122 for Dingell – but that does not make it any less significant as an indicator of the direction Congress is likely to take in a period when Democrats will control the executive and legislative branches of a federal government that Waxman thinks should be far more activist in its approach to environmental issues and the regulation of corporations.

That said, the Waxman-Dingell fight was never a precise left-right struggle.

Much of the media portrayed Waxman, the activist chair of the House Oversight and Government Reform Committee in the current Congress, as the liberal contender. And there is no question that, as the Bush-Cheney administration became increasingly excessive, the Californian was among its loudest and most powerful critics on the Hill – especially during debates on regulatory concerns that have too often been neglected by committee chairs who fail to utilize their broad investigatory powers. Waxman has, as well, been one of the steadiest critics of corporate wrongdoing on the Hill and a genuine ally of the consumer movement.

Dingell, who at 82 is the longest-serving member the current House, was characterized as the conservative player. But that was always more a matter of media shorthand than reality.

Dingell opposed authorizing George W. Bush to attack Iraq, rejected the Patriot Act from the start and has been a stalwart opponent of free-trade deals. The Michigan congressman has, as well, been the House’s longest and steadiest advocate for a national healthcare plan.

Waxman, at 69 another House veteran, voted to authorize George Bush to take the country to war with Iraq, backed the Patriot Act and has abandoned the fair-trade position to back a number of free-trade initiatives opposed by labor, farm and environmental groups. (To his credit, Waxman acknowledged to this reporter several years ago that he was wrong on the war and has a generally strong record on civil liberties issues.)

Both contenders had progressive backers – with those for Dingell, long seen as the auto industry’s man on Capitol Hill, coming more from members aligned with organized labor, while Waxman’s were often younger and more engaged with environmental causes.

From the start of the chair race, there was a sense in the House that Waxman had one supporter who, though she did not actively campaign on his behalf, ranked above all others. Few doubted that House Speaker Nancy Pelosi wanted her fellow Californian and long-time ally to take charge of the Energy and Commerce Committee.

Pelosi’s allies in the House suggested – sometimes quietly, but toward the close of the competition more bluntly — that Waxman would be a better fit as chair of a committee that will be critical to advancing the agenda of Barack Obama’s administration on the energy, environmental, health care, consumer protection and telecommunications issues that are likely to be among the new president’s top domestic priorities.

“The next two years are critical,” argued Illinois Congresswoman Jan Schakowsky, a Pelosi ally and Waxman backer. “It’s not personal. It’s about the American people demanding that we embrace change and work with the president on critical issues of climate change and energy and health care.”

Waxman reinforced this message, arguing that: “We have a new opportunity that only comes once in a generation. We must meet the challenge.”

The Obama transition team, while officially neutral in the contest, was seen by some as weighing in when it signaled prior to the caucus vote that Phil Schiliro, Waxman’s former chief of staff, would serve as assistant to the president for legislative affairs. Effectively, Schiliro will be the president’s top lobbyist on Capitol Hill.

What, then, can we take away from this shift in the chairmanship of one of the House’s key committees?

1. Pelosi is more powerful than ever, arguably the most powerful speaker in decades. She has established a leadership team that is closely aligned with her, and appears to be getting the remaining committee chairs in line.

2. Pelosi and Obama appear to be on the same page, and are beginning to outline the structures of a close working relationship on domestic issues.

3. The focus on Energy and Commerce, as well as the expected appointment of former Senate Majority Leader Tom Daschle as the new Secretary of Health and Human Services and the selection of Schiliro as the White House’s chief lobbyist, suggests that Obama is preparing to make a major push on health care, and that Waxman will be key to that push.

4. The auto industry may yet get its bailout, but it will be under more pressure than even to radically change its approach, especially on environmental issues. This is not to suggest that Dingell did not care about the environment – he had, in recent years, taken up climate charge issues – but that Waxman is far more focused on this front.

5. Corporations, no matter what sector of the economy they operate in, are likely to find themselves facing more scrutiny from the Energy and Commerce Committee. Waxman has a very long record of embracing and advancing the regulatory and investigative agendas of the consumer movement.