Rep. Barney Frank, D-Mass., the Financial Services Committee chairman, said the rescue bill was just the beginning of a much larger task Congress will tackle next year: overhauling housing policy and financial regulation in a legislative effort he compared to the New Deal.

"We were the EMTs rushing to the rescue of an economy that suddenly found itself choking, but now we have to perform more serious reform," Frank said.

Just four days earlier, the previous version of the bill was sent down to defeat, largely at the hands of angry conservative Republicans. On Friday, a total of 33 Democrats and 25 Republicans switched from opposition to support. In all, 91 Republicans joined 172 Democrats to support the measure while 108 Republicans and 63 Democrats voted "no."

The reversal reflected a high-stakes political environment. Some lawmakers were worried about their own jobs, but others — mostly Democrats — focused on the prospect that a new president could have a far more significant effect on the economy than any one piece of legislation.

Several of the Democratic switchers were members of the Congressional Black Caucus who said they changed course after securing commitments from presidential candidate Barack Obama that he would back legislation to help struggling consumers and homeowners facing foreclosures if he wins the White House.

"It's not too often you get the future president telling you that his priority matches your priority," said Rep. Elijah Cummings, D-Md., one of 13 black lawmakers who switched from "no" to "yes."

Republican presidential candidate John McCain also lobbied for the measure, according to aides who declined to say whom he called.

Rep. Roy Blunt, R-Mo., the party vote-counter, said McCain phoned Rep. John Shadegg, a fellow Arizonan who switched to "yes."

The legislation's roller-coaster ride through Congress began at a somber meeting in Pelosi's office in mid-September, where Paulson and Federal Reserve Chairman Ben Bernanke frightened senior Democrats and Republicans with their warnings of an impending economic collapse without quick legislative action.

As lawmakers scrambled to draft a bill, they were barraged by angry calls from constituents to reject what many saw as a huge giveaway to the very financial institutions that helped cause the subprime mortgage meltdown at the root of the economic crisis — with nothing to help its ordinary victims.

"Pray for our republic," intoned Rep. Marcy Kaptur, D-Ohio, a leading opponent of the measure. "She's being placed in very uncaring and greedy hands."

Supporters said the prospect of economic disaster superseded their political fears.