WASHINGTON — President Obama's landmark energy and global warming bill squeaked through the House only after the White House made dozens of concessions to coal, manufacturing and other interests.
Now, as the battle moves to the Senate, Obama faces demands for even more concessions -- including pressure to open the nation's coastlines to offshore oil and gas drilling.
The Senate also will take up a series of controversial issues that were glossed over or omitted from the House legislation. Among them: giving the government sweeping powers to approve thousands of miles of new transmission lines to carry electric power to coastal cities from wind turbines in the upper Midwest and solar power generators in the Southwest, regardless of local objections.
Aware of the challenge, Obama repeatedly has called attention to the House achievement and urged the Senate to keep up the momentum.
"There are going to be a series of tough negotiations," he said last week. "But I think the ability of the House to move forward is going to be a prod for the Senate toward action."
Even so, with Republicans forming a near-solid phalanx of opposition and many Democrats concerned about the effects of specific sections of the bill on their constituents, the prospect is for a long, slow legislative process.
Senate leaders say they will benefit from lessons learned from the way House leaders built their majority. Chief among them: the need to cut specific deals to ease the effects of new emissions restrictions -- which could translate into higher costs for businesses and rising prices for consumers -- in particular parts of the country.
"We need to absolutely work this bill one on one," said Sen. Barbara Boxer (D-Calif.), who chairs the Environment and Public Works Committee that is drafting emissions limits, "because everybody's got different passions about it, different feelings about it, different hopes about it, different fears about it."
Making those deals is harder in the Senate than in the House, some analysts say.
"In the House, you can move blocks of votes," said Daniel Weiss, a senior fellow at the liberal Center for American Progress who works on global warming issues. "In the Senate, it's hand-to-hand combat."
Although a climate bill is expected to be hundreds of pages long, it will boil down to an attempt to start weaning the U.S. economy from dependence on fossil fuels.
The centerpiece is the so-called cap-and-trade system, which would set limits on carbon dioxide and other emissions that scientists say are a major factor in global warming. The allowed level of such emissions would decline over time. And major polluters, such as power plants and factories, would be required to obtain permits to cover their emissions as a spur to reducing pollution.
The original idea was that the government would sell the permits, but the House voted to give out many of them free to ease the economic effects.
The Senate bill also is likely to include a variety of provisions designed to encourage development of energy sources, including wind and solar power. Those could include financial and legal provisions to speed construction of transmission lines to move power from the remote deserts and plains -- where it's easily produced -- to coastal cities where it's needed.
The quest for new energy sources is expected to reopen the politically explosive issue of offshore drilling.
Looming over all the provisions is cost -- a focal point of Republican attacks.
"The public is especially wary of passing this during a major recession, and public skepticism is growing about the man-made climate fears," said Marc Morano, editor of the global-warming-skeptic website ClimateDepot.com.
Democrats and the two independents who caucus with them control 60 Senate seats. But more than a dozen have expressed concern over costs. They include Democrats from industry-heavy Ohio and Michigan, coal-dependent Indiana and oil-rich Louisiana.
Only a few Republicans appear open to emissions limits, notably two moderates from Maine -- Sens. Susan Collins and Olympia J. Snowe -- and Sen. John McCain of Arizona, who championed emissions limits in his presidential campaign (though he has expressed reservations about the House bill).
The Senate bill will emerge from several committees -- including the finance, foreign relations, commerce and agriculture committees -- with dramatically different memberships and priorities.
The energy committee already has approved its chunk with wide bipartisan support. It includes a requirement to produce more electricity from renewable sources, but also expands drilling -- a possible deal-breaker for environmentalists.
Boxer's committee will center its work on cap and trade. The House bill would cut U.S. emissions by 17% below 2005 levels by 2020 and 83% by 2050. Environmentalists expect Boxer, who said she was "looking closely" at those limits, to strengthen them.