Congressional Democrats and Republicans traded accusations Monday over what and whom to blame for the financial crisis amid startling new revelations surrounding the bankruptcy of the Lehman Brothers investment bank.

Democrats aimed their harshest attacks at deregulation and CEO pay, using former Lehman Chairman and Chief Executive Officer Richard Fuld as an example during a recess hearing of the House Oversight and Government Reform Committee.

Republicans, for their part, launched a campaign to pin the financial meltdown on Fannie Mae and Freddie Mac, and attacked Waxman for not holding a hearing to dig into the now-nationalized mortgage giants.

“Any hearing on oversight that does not begin with Fannie and Freddie and [former Fannie Mae CEO] Franklin Raines will be a sham,” said Rep. John Mica (R-Fla.). “This is like investigating a train robbery and only talking to the dining car stewards.”

The GOP attack from the dais came as the National Republican Campaign Committee and House Minority Leader John Boehner (R-Ohio) sent nearly simultaneous news releases criticizing Fannie and Freddie.

Boehner’s statement echoed Mica’s, saying, “Chairman Waxman’s refusal to hold hearings to examine their role says a lot about where the Democrats’ priorities lie.”

The mortgage giants aren’t part of the five-hearing investigation Waxman is planning for the rest of October, but Waxman said he is looking into their failure. He said committee staffers are reviewing documents and he might call a hearing.

“I don’t think we ought to use these hearings to be partisan,” Waxman said. “To look at Lehman is appropriate. To look at Fannie Mae and Freddie Mac is appropriate.”

Waxman also retorted that looking back at Congress’s interaction with Fannie Mae could be dangerous territory for the GOP, since it controlled Congress for 12 years until 2007.

The presidential campaign played a key role at the hearing, with Republicans pointing to Barack Obama’s national finance chairman’s involvement in a bank failure, and Democrats highlighting an embarrassing e-mail from President Bush’s cousin, a Lehman board member, that mocked attempts to rein in executive compensation.

The e-mails showed Fuld and Bush’s cousin, George H. Walker, mocking a recommendation from a Lehman subsidiary that executives give up their bonuses.

“Sorry team,” Walker wrote in the e-mail. “I’m not sure what’s in the water at 605 Third Avenue [the address of the subsidiary] today. I’m embarrassed and I apologize.”

Fuld added in an e-mail, “Don’t worry, they are only people who think about their own pockets.”

In a two-hour run-up to Fuld’s testimony, Democrats chomped at the bit to sink their teeth into the former CEO, having pored over his prepared statement and found he did not take responsibility for Lehman’s failure.

“He’s going to come in here and say it was everybody’s fault but his own,” said Rep. Elijah Cummings (D-Md.). “The people on my block, in Baltimore, if they do poorly, they get fired. They don’t get a bonus.”

But Fuld, who’d listened to the first part of the hearing, headed off the lawmakers when he sat down at the witness table by taking responsibility.

“I want to make one thing clear,” Fuld said. “I take full responsibility for the decisions I made and the actions that I took. With the benefit of hindsight, would I have made decisions differently? Yes.”