After a flashy press conference with business leaders and environmentalists, the chief authors didn’t even formally introduce the bill. They barely discussed it with their colleagues at the weekly party luncheons.

But off the Hill, interest groups mined the 957-page proposal and divided into camps in support of or against the bill. Some beefed up their lobbying efforts to amend the proposal, while others backed away from it entirely.

Sens. John Kerry (D-Mass.) and Joseph Lieberman (I-Conn.) are being deliberate about how they move their proposal forward, taking time to curry support from those groups as well as industry leaders like oil tycoon T. Boone Pickens .

Their bill may still face a referendum soon. Sen. Lisa Murkowski (R-Alaska) has about three weeks left to call for a vote on her resolution blocking the Environmental Protection Agency from regulating greenhouse gases.

That bipartisan proposal could decide what happens with the Kerry-Lieberman proposal, the New York Times reports:

Many observers see Murkowski's resolution as doomed, in part because it is unlikely to win President Obama's signature if it clears both chambers of Congress or withstands a veto. But even if it fails, observers say the vote could signal whether the Senate is prepared to quash or kick-start the climate bill.

Advocacy groups have tried to weigh in on the Murkowski vote for this reason. The Union of Concerned Scientists sent a letter with more than 1,800 signatures asking lawmakers to vote against the proposal.

Dozens of agricultural groups, including the American Farm Bureau Federation , lined up on the other side, saying Congress – not the E.P.A. – should decide how greenhouse gases are managed.

Lawmakers already seem skeptical about the climate bill's chances. They senators need 60 votes at a time when lawmakers are particularly sensitive about the upcoming election season.

"My feeling is it's not going to be coming up this year, but if it does I will dig into it at great depth," Sen. Carl Levin (D-Mich.) told Reuters .

In addition, the powerful transportation lobby plans to fight the bill. The groups represent truckers, public transit companies and workers, motorists, and construction workers.

The coalition of 28 organizations argues that the climate bill takes money away from the nation’s crumbling infrastructure of highways, bridges, and public transit, the Pittsburgh Post-Gazette reports.

A key aspect of the Kerry-Lieberman bill is charging transportation companies a fee for using carbon fuel. The groups say that money should go back into building public transit, rather than to reducing the deficit or tax refunds.

Environmental groups are split on the proposal. Groups like the Natural Resources Defense Council and League of Conservation Voters have called on President Obama to show leadership on this issue and urge the senate to pass this bill.

At the same time, a Climate Reality Check coalition has emerged with organizations like Friend of the Earth, which have been skeptical of industry involvement in the Kerry-Lieberman bill. That group has asked lawmakers not to support this proposal, saying it would actually do more harm than good to the environment.

The World Wildlife Fund has increased its lobbying budget by 600 percent in the last year with the hope of amending the bill. The group wants the bill to focus more globally and invest in clean technologies in developing countries, according to the New York Times .

A new set of reports on climate change may affect the debate, too. The National Research Council made a splash this week by unveiling three reports that urge the U.S. to take quick action on climate change.

Congress requested the arm of the National Academy of Sciences to research the topic, and the National Oceanic and Atmospheric Administration paid for the publications. One scientist called it “the most comprehensive report ever on climate change.”

The reports may help Kerry and Lieberman make the case for a cap on greenhouse gases for the nation’s biggest pollutants, but they may also be used by environmentalists to argue that the proposed bill doesn’t go far enough.

“We really need to get started right away. It’s not opinion, it’s what the science tells you,” one of the reports authors told the Seattle Times .