Another expression of disgust came from Senator Jim Bunning, Republican of Kentucky, who said the plan would “take Wall Street’s pain and spread it to the taxpayers.”

“It’s financial socialism, and it’s un-American,” Mr. Bunning said.

Senator Dodd called the crisis “entirely foreseeable and preventable, not an act of God,” and said that it angered him to think about “the authors of this calamity” walking away with the usual golden parachutes while taxpayers pick up the bill.

“There is no second act on this,” Mr. Dodd said, acknowledging that speed was important. But it is more important, he said, “to get it right.”

Mr. Paulson said in response to questions that he shared the senators’ exasperation. “I’m not only concerned, I’m angry” over the events that led to the problem, Mr. Paulson said. He blamed an outdated regulatory system for the turmoil and, in an effort to counter any impression that the proposed rescue plan is for the benefit of fat-cat Wall Streeters, said: “This is all about the taxpayers. That is all we are about.”

Mr. Paulson said that “this troubled asset purchase program is the single most effective thing we can do to help homeowners, the American people, and stimulate our economy.”

He and Mr. Bernanke said that the problems in the housing industry were the core of the crisis but that the problems would continue to spread far outside the housing sector if the problems in the mortgage markets were not addressed, and soon.

With global financial stresses and uncertainties continuing to play out, Mr. Bernanke warned in his testimony that “if financial conditions fail to improve for a protracted period, the implications for the broader economy could be quite adverse.” He reminded the senators at one point that he had never worked on Wall Street and was instead an economic scholar who had studied earlier financial crises, including the Depression.