Rep. Henry Waxman’s successful coup against Energy and Commerce Chairman John Dingell on Thursday leaves the storied former chairman with a ceremonial role and steers the Democratic agenda sharply left.

The 137-122 vote to hand Waxman (Calif.) the gavel dealt a serious challenge to the Democrats’ seniority system and put key aspects of President-elect Barack Obama’s agenda in the hands of a liberal, aggressive and activist chairman.

Dingell (Mich.) congratulated Waxman in a statement after the vote, alluded to Obama’s “change” theme, and indicated he intends to stay in Congress.

“This was clearly a change year and I congratulate my colleague Henry Waxman on his success today,” Dingell said. “What will not change, however, and what will never change, is my commitment to the working men and women of the 15^th congressional district of Michigan.”

Centrists and adherents to the seniority system were left fuming that Dingell was unseated. Some said the political and personal wounds won’t quickly heal, especially as Dingell remains on the Energy and Commerce dais as “chairman emeritus.”

“I think it was highly inappropriate. There was no obvious reason to make this change,” said Rep. Rick Boucher (D-Va.), a Dingell whip and an ally on the measured approach to climate change. Another centrist Dingell supporter called the vote “an outrage.”

Even a Republican, fellow Michigan Rep. Thaddeus McCotter, criticized Democrats for ousting Dingell. He noted that it came on the same day that a bailout for automakers collapsed in Congress.

“For working families, the American auto industry and our entire manufacturing base an already dim day has grown darker, due to this internecine betrayal of Chairman Dingell,” McCotter said in a statement.

House Ways and Means Chairman Charles Rangel (D-N.Y.), a senior, liberal member, called it a blow to the seniority system. “It’s just been buried,” he said.

After the vote, Waxman said seniority is important, but not preeminent.

“People can run against us back home if they think we can do a better job, and people should be allowed to run against us here in the Congress if they think they can do a better job,” Waxman said. “Seniority is important. But it should not be a grant of property rights to be chairman for three decades or more.”

Particularly upset were the conservative Blue Dog Democrats. One member said they were “in orbit — they think it’s a California takeover.”

Publicly, the Blue Dogs were slightly more circumspect.

“We’ll work with the new leadership,” said Rep. Stephanie Herseth Sandlin (S.D.). “But to deny a man who defines the modern Congress ... is a mistake.”

Rep. Charlie Melancon (La.), a fellow new Blue Dog leader, agreed that centrists are still willing to work with Waxman.

“Give the man the opportunity to demonstrate that we’re not going ‘hard left,’ or ‘off the cliff’,” Melancon said. “There’s no fears, but there’s some concerns.”

Melancon said he was bothered that the caucus would dump Dingell when he was expected to retire at the end of this Congress.

But some Dingell supporters also conceded that Waxman’s quiet campaign had a superior whip operation. And others saw in Dingell’s defeat the hand of House Speaker Nancy Pelosi (D-Calif.). She was officially neutral, but also never stepped in to end Waxman’s challenge.

“I assume that not playing a role is playing a role," Rangel said.

In a statement after the vote, Pelosi did not stray from her public neutrality. She praised Dingell and predicted unity, but extolled Waxman as the man to carry forward the issues she has identified as priorities for Obama and herself as Speaker.

“Under his leadership, the committee and the entire caucus will make progress toward making America energy-independent, making healthcare available to all Americans, and addressing the greatest challenge of our time, global warming,” Pelosi said.

And supporters of a more aggressive approach to climate change and more aggressive regulation were encouraged. Dingell was a chief advocate of automakers and was slow to warm up to Pelosi’s call for restrictions to limit climate change.

“I think it will be easier,” Rep. Earl Blumenauer (D-Ore.) said of global warming restrictions. “I think anyone who’s watched the last couple of years would conclude it will happen more quickly and more smoothly. [Waxman] is better positioned to guide that.”

Supporters also said they wanted swifter implementation of the agenda of the Democratic Party and Obama.

Rep. Howard Berman (D-Calif.), a Waxman ally for years, said Waxman supporters were mindful of 1993 and 1994 when Democrats controlled Congress and the White House for two years, then lost Congress in a dramatic fashion.

“The memory of ’93 and ’94 was seared into our minds," Berman said. "We have to pass the program. The question was how that could best be done.”

Inside the caucus room, Reps. Mike Doyle (D-Pa.), Herseth Sandlin, Diana DeGette (D-Colo.) and John Lewis (D-Ga.) spoke for Dingell.

Supporters focused on Dingell’s years of work and successful legislation as chairman of the committee.

“The focus was on his tremendous congressional service,” said Boucher. “That record of achievement deserves to be rewarded.”

Waxman spent most of his allotted time speaking on his own behalf. But Reps. Elijah Cummings (D-Md.), Bruce Braley (D-Iowa) and Jan Schakowsky (D-Ill.) also spoke for him.

Schakowsky even brought props to demonstrate the changes Waxman engineered in the daily lives of Americans. She held up a bag of potato chips to point out the nutrition label he pushed for. She held up a pill bottle to signify his push for generic pharmaceuticals and an apple that she said was safer because of Waxman’s efforts on pesticides.

“He can get the job done and pass legislation,” Schakowsky said later. “The top issues of the Obama administration are what he’s been most active on.”

After the vote, Pelosi called for Dingell to be named “chairman emeritus,” which gives him a title, but no authority.