Rep. Nancy Pelosi’s (D-Calif.) moves since the November elections have shaken up some of her colleagues, with some looking over their shoulders and others worried about how the Speaker will lead her expanded majority in 2009.

Next year is regarded as the biggest legislative opportunity for Democrats since 1993, the last time they controlled the White House and both chambers of Congress.

Contrary to the jubilation of House Democrats after they regained control of the lower chamber after the 2006 elections, there is some unease among members heading into the 111th Congress.

“Everybody I talk to, everybody’s worried about something,” said a Democratic staffer.

Pelosi’s effort to make some Democrats anxious could be a calculated maneuver as she seeks to maximize the effectiveness of her caucus heading into 2009. Pelosi’s hard-charging tone and decisions over the past month have sent a message to her colleagues: Don’t get too comfortable.

The seniority system that tempers the power of the Speaker is teetering, having received a body blow from Rep. Henry Waxman’s (D-Calif.) coup at the Energy and Commerce Committee.

When chairmen aren’t flinching at the possibility of a challenge from a junior member, they can look forward to being bounced by term limits in four years. That’s a change that Pelosi quietly endorsed in the 2007 House rules package.

Throughout the past four years, there has been a palpable strain in the Democratic Caucus between the older members who extol the seniority system and younger legislators who believe they deserve a more significant role in decisionmaking.

Pelosi, the unquestioned leader in the House whose enormous power seems to grow by the day, has sought to placate both factions. And to this point, she has succeeded.

Few members clash publicly with Pelosi. Reps. John Dingell (D-Mich.) and Jane Harman (D-Calif.), who were at odds with Pelosi over the last few years, were stripped of their top committee posts.

Centrists are grumbling that their growing ranks aren’t represented in the leadership team that Pelosi shaped through back-room arm-twisting. The so-called Blue Dogs, while publicly celebrating President-elect Obama’s commitment to “pay-go,” are wondering when the stimulus balloon stops expanding.

There is also growing speculation that pay-go will be waived for healthcare legislation, which is expected to cost hundreds of billions of dollars.

Meanwhile, Congress has swept in and out of town since the election with little to show except for a deposed chairman and a tongue-lashing for auto executives. And to the extent that any decisions are being announced, they’re coming from Obama’s headquarters in Chicago.

Most leadership aides, for their part, say any talk of tension is exaggerated. The word out of Pelosi’s office is not to worry.

“Everyone had and will continue to have a seat at the table,” said Pelosi spokesman Nadeam Elshami. “Her record has been that she’s a pragmatist who gets things done.”

On the day after the election, Pelosi assured that “the country must be governed from the middle.”

But as she spoke, Waxman was seeking to move things to the left. He spent the day making calls to fellow members asking them for the gavel of Energy and Commerce, where the heart of the Obama agenda will be hammered out. About two weeks later, the environmental left prevailed over the business-minded centrists when Dingell, the champion of the auto industry, was ousted.

“We’ll work with the new leadership,” Rep. Stephanie Herseth Sandlin (D-S.D.), incoming leader of the conservative Blue Dogs, said after the Dingell vote. “But to deny a man who defines the modern Congress ... is a mistake.”

Pelosi insists she had nothing to do with it. Her aides claim that she stayed strictly neutral even though Waxman hails from her state and Education and Labor Committee Chairman George Miller (D-Calif.), a Pelosi confidant, lobbied heavily for Waxman.