After a hard-fought victory on health care reform, President Barack Obama's allies in Congress are setting their sights on climate change -- but some on both sides are already crying foul.
Environmentalists hope Obama will seize on new political momentum to push forward climate legislation, though some observers question whether he would seek another divisive vote as November congressional elections approach.
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Sen. John Kerry, who has spearheaded climate legislation, said White House officials can now "pour their energy and attention" into the issue after Sunday's down-to-the-wire vote on expanding healthcare coverage.
"In the wake of healthcare's passage, we have a strong case to make that this can be the next breakthrough legislative fight," the Massachusetts Democrat argued.
"Climate legislation is the single best opportunity we have to create jobs, reduce pollution and stop sending billions overseas for foreign oil from countries that would do us harm," Kerry said.
"If we sell those arguments we've got a winning issue on jobs, on security and on public health. This can happen."
The House in June approved a bill that would start the country's first nationwide "cap-and-trade" system that restricts carbon emissions blamed for global warming and allows trading in credits.
The Senate has yet to offer companion legislation, despite pressure on the United States to finalize an action plan before December's climate summit in Copenhagen.
Unlike healthcare, which split on sharply partisan lines, Kerry voiced confidence in winning Republican support. He is working on climate legislation with Republican Sen. Lindsey Graham of South Carolina, a vociferous foe of Obama's healthcare plan.
But the odd-couple alliance, which also includes independent Sen. Joe Lieberman of Connecticut, has raised concern among some green groups.
Some greens were already disappointed with the House bill, which would curb emissions by 17 percent by 2020 from 2005 levels — much less than promises from the European Union and Japan, which use a 1990 baseline.
Kerry and Graham have sought to woo support by meeting with leaders of businesses that have concerns about the legislation including oil companies.
The legislation is likely to back nuclear energy and offshore oil drilling, anathema to some environmentalists, and may reduce the reliance on a cap-and-trade system.
"If the senators feel it's their job to move from what was one of the biggest corporate giveaways in American history to make something that's even more friendly to polluting industry, that would be a huge mistake," said Nick Berning, public advocacy director at Friends of the Earth.
Some Republicans have sought to strip the Environmental Protection Agency of the right to regulate carbon dioxide as part of a compromise — a step Berning said would be a "huge step backwards."
But Eric Haxthausen, director of U.S. climate policy at The Nature Conservancy, said it only advanced the cause of climate legislation for environmentalists and industry to work together.
"It's tempting to say that you're watering this down. But what's important is the fact that you can get an engagement from a sector that hasn't been engaged in the process," he said.
Despite Graham's support, most Republicans remain opposed to action on climate change, arguing that it will harm an already fragile economy.
Republican Sen. Scott Brown, who won a special election in January in Massachusetts, is critical of climate legislation. Rep. Mark Kirk of Illinois, one of only eight Republicans to vote for the bill in June, has changed course as he seeks a Senate seat.
Ben Lieberman, a senior policy analyst at the conservative Heritage Foundation, said it would be "enormously complicated" to draft a climate and energy bill that satisfies all sides.
"There may or may not be time for another initiative" after healthcare, Lieberman said. "There's not a lot of time between now and when legislators have to get serious about elections."