Sen. Arlen Specter's party switch sent shockwaves across Washington yesterday, but it appears unlikely to significantly alter the prospects for President Obama's agenda on energy, climate change and other major legislation.

Certainly, Senate Democrats were visibly overjoyed with the prospect of holding the 60-vote majority that they have long coveted, as it should make it easier for the party to clear procedural hurdles. But top Democrats cautioned that they would still need to compromise -- both within their own party and perhaps with the GOP -- to cobble together enough votes to pass major legislation.

"Anyone who says now that the president's agenda can slide right through is wrong; that will not happen," said Sen. Charles Schumer (D-N.Y.), the third-ranking member in the Senate Democratic leadership.

As for the calculus on one of the biggest legislative and political battles facing the Senate -- climate change -- it does not appear much of anything has changed.

"It does not change that," Senate Environment and Public Works Chairwoman Barbara Boxer (D-Calif.) said of the prospects for climate change legislation. "I don't think climate change is a matter of party. It is really more a matter of region. So I don't think it changes that much."

As a senator from Pennsylvania, Specter represents a state that has a heavy manufacturing base and still leans on coal for a significant number of jobs -- though less so than in the past.

Sen. Debbie Stabenow (D-Mich.) who has formed a coalition of 16 Democratic senators from manufacturing and coal-reliant states to work on the climate change issue, told reporters that she viewed Specter as something of a kindred spirit. "He comes from an important state that has a lot of similarities to mine," she said. "I am sure he will be an important voice."

"My views on cap-and-trade are pretty explicit," Specter said yesterday when asked about climate change.

Specter has cosponsored cap-and-trade legislation with Energy and Natural Resources Chairman Jeff Bingaman (D-N.M.), though his support hinged on inclusion of a "safety valve" price ceiling, as well as less aggressive emission targets than some of the other competing bills.

And Specter in recent weeks opposed a proposal to fast-track climate change legislation through the budget process but said the issue is something that Congress needs to address this year. "I think it's going to be tough to do, but I think it's something we ought to get done," he said last month (E&E Daily, March 26).

That is not to say that the prospects for the bill have not changed at all with Specter's switch. If Specter had stayed with the Republicans and was in the midst of a heated primary battle, he may have been under heavy pressure to oppose a climate change bill that is overwhelmingly unpopular with the GOP base.

Instead, Specter is now a member of a party where climate change generally polls well and where key constituencies -- labor and environmentalists -- are vigorously pushing for the issue.

"Needless to say, as a Republican facing a tough primary challenge from the right, he was a lost vote on global warming legislation," Joe Romm, a climate expert with the liberal Center for American Progress, wrote on his blog. "One assumes that if he is going to seriously run as a Democrat, he'll support an energy and climate bill."

The co-sponsor of a House bill to be marked up next month said Specter's decision will help in the long run. "It increases the chances without question," said Rep. Ed Markey (D-Mass.), chairman of the Energy and Environment Subcommittee where a climate bill is now pending.

Markey cited his work negotiating cap-and-trade legislation with interests critical to Pennsylvania. "He is sincerely interested in finding a solution to the climate change issue, which is why we're working with the steel and coal industries, which would be Pennsylvania-affected industries," he said.

But Rep. Rick Boucher (D-Va.), a key House moderate, said Specter's flip would have little influence because the focus is squarely on the House Energy and Commerce Committee moving first on the climate bill.

"That would offer the Senate a clear path forward in terms of how to legislate on climate change," Boucher said. "If we're not able to achieve that broad consensus within the committee, then I'm not sure this measure advances in either house. I'm not sure adding another vote in the Senate really changes anything all that much."

No more filibusters?

Specter's defection from the GOP will almost assuredly give Democrats the magic 60 votes and filibuster-proof majority. Specter will become the 59th lawmaker to caucus with the majority party, with Al Franken in Minnesota -- pending the resolution of the court case surrounding that election -- poised to be the 60th.

Specter himself made it clear that even as he changes his party affiliation, he does not believe that there will be any fundamental change in his beliefs or voting pattern. "I will not be an automatic 60th vote," Specter said. "If the Democratic Party asks too much, I will not hesitate to disagree and vote my independent thinking."

The Pennsylvania senator was not asked to make any promises of support for the Democratic agenda or to vote in favor of any particular issues, according to Senate leadership aides familiar with the negotiations between Specter and Majority Leader Harry Reid (D-Nev.). Reid told reporters yesterday afternoon that he does not view Specter as an "automatic vote."

Specter has long held a reputation as a moderate willing to buck his party on high-profile issues. He angered conservatives with his opposition to President Reagan's nomination of Robert Bork to the Supreme Court and for his pro-choice position on abortion -- a stance that almost cost him the chairmanship of the Judiciary Committee four years ago.

And Specter again tried to brandish his independence yesterday, saying that he was opposed to the "card check" bill that is a major priority for many Capitol Hill Democrats and organized labor. "The principles that I subscribe to are my independence, which I will retain regardless of party label," he said.

Likewise, Specter said he will have no hesitation about butting heads with fellow Democrats on any number of issues. "It all depends on whether those fellow Democrats are wrong or stubborn," Specter joked. "And if they are, I will butt heads with them. And if they're reasonable, that is agree with me, copasetic."

Sen. Ben Nelson (D-Neb.), a moderate Democrat who also at times bucks his party leadership, also said there was little expectation that Specter's presence in the caucus would automatically guarantee his vote.

"Sixty members does not translate or transfer into 60 votes," Nelson said. "The fact that he has switched parties does not mean he's going vote consistently with the party line."

Vice President Joe Biden, a former Senate colleague of Specter's, agreed the Pennsylvanian will maintain his independence. "Arlen is now freed up to vote in a way that he doesn't have to worry about angering his leadership," Biden said at a Democratic fundraiser in Houston yesterday.

Specter's seniority

Specter's decision could also reshape the Democratic committee leadership lineup.

Reid and Specter said yesterday that even as the Pennsylvania senator switches parties, he will be allowed to keep all of the seniority that he accumulated since he came to the Capitol in 1980. That would automatically make Specter among the most senior Democrats on both the Judiciary Committee -- where Specter was the ranking member -- and the Appropriations Committee -- where he was the ranking member on the Labor-Health subcommittee.

It is unclear what ramifications that would have in the short-term and what posts Specter will hold for the remainder of the 111th Congress.

Reid said he has made clear to Specter that no Democrat will lose a chairmanship, unless they are willing to take such a step. "Senator Specter knows that no one will be dumped off the full committee or subcommittee unless it's done on a voluntary basis," Reid said.

Specter has less seniority than current Judiciary Chairman Pat Leahy (D-Vt.) so he has no short-term hope of getting that gavel, but he does outrank current Labor-Health Appropriations Subcommittee Chairman Tom Harkin (D-Iowa). Should Specter somehow take the gavel of the subcommittee, it would almost certainly cause a chain reaction that would reverberate through the other spending committees, including those that handle energy and environment appropriations.

Reid said he has not yet spoken with Harkin about his spending committee.

But 2011 will be a new ballgame. "In a year and half it's a new game, and Senator Specter has seniority on a number of committees that he wants to serve on," Reid said.

Specter openly admitted that he has an interest in one day claiming the chairmanship of the powerful Senate Appropriations Committee. "It is something I'd like to attain," Specter said of the chairmanship. "I can't deal with the numbers. You know who the people are and who is going to run for re-election and who's going to do what remains to be seen."

Specter would be forth in seniority among Senate Democrats in that committee, behind current Chairman Daniel Inouye (D-Hawaii), former Chairman Robert Byrd (D-W.Va.) and Leahy.

Reporters Ben Geman, Darren Samuelsohn and Josh Voorhees contributed.