"A bill with a price on carbon is still a very difficult thing to deliver," said Michael A. Levi, director of the program on energy security and climate change at Council on Foreign Relations. "On the other end of the spectrum, a bill that gently promotes alternative energy and reforms regulations for offshore drilling and liabilities is relatively easy. The question is what do you get in between."
A number of bills related to energy and climate have been proposed in the Senate.
The much-touted Kerry-Lieberman "American Power Act" seeks to cut carbon pollution by 17 percent in 2020 and by more than 80 percent by 2050, but it's seen as a non-starter by many. A bill by Sen. Dick Lugar, R-Indiana, calls for more fuel efficiency programs and energy efficiency but doesn't include any specifics on carbon caps and regulating greenhouse gases.
Sens. Susan Collins, R-Maine, and Maria Cantwell, D-Washington, introduced a bipartisan "cap and dividend" bill last December, under which polluters would pay to buy "carbon shares" in an auction, the money from which would go toward clean energy research and into Americans' pockets. Yet another handful of bills have been offered in the wake of the Gulf of Mexico oil spill.
The final product is likely to be a combination of all the various proposals, crafted chiefly by Sen. Harry Reid, D-Nevada.
But whether there will be enough support to pass it remains to be seen. Byrd's successor has yet to be announced, and given West Virginia's deep-rooted history as a coal mining state, any incoming senator will have to be convinced of the merits of an energy bill. At the same time, Democrats will need the support of at least a few Republicans, who have so far been hesitant to associate themselves with any carbon caps.
"One of the things that I learned is that you not only have normal partisan divisions, you also have regional divisions that are pretty strong, so energy-producing-state senators, for example, tend to be very similar in their views, and so that changes the normal dynamics," Abraham said.
Some senators are also concerned about putting too much on their plate in a contentious election year, when the Democratic agenda is likely to be put under increased scrutiny.
Abraham said given the politics of energy, it is unlikely that a comprehensive energy bill will pass Congress, especially in an election year in which many Democrats are wary about their reelection prospects.
"I think it will be hard to pass a bill the magnitude of the House bill," he said. "I think it's going to be an uphill fight because you have not just Republican Democrats disagreeing but you have the regional disagreements and you have the deep concerns about the economic consequences of passing a lot of regulatory implications."
The president continues to urge Senators to pass a bill -- he made that issue a central point of his first address from the Oval Office -- but the White House has offered limited guidance on what it would like to see in a bill, much to the chagrin of some Democratic senators.
Obama needs to be clear about the outcomes that the bill will need to produce, Levi said.