In one hearing in 2009, Warren grilled Geithner about what she felt were differing standards for the conditions of the U.S. automobile-industry bailout as opposed to more lax standards for financial institutions that received bailout money.
"You're saying there have been changes in management?" Warren asked about financial institutions, to which Geithner responded, there were changes at American International Group as well as at Fannie Mae and Freddie Mac.
"I am asking about the banks," Warren responded.
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"Going forward, where institutions need exceptional levels of assistance, we will make sure that assistance comes with conditions that provide for the necessary degree of accountability, help ensure these firms emerge stronger rather than weaker," Geithner said.
In another hearing, Warren probed Geithner about where the money AIG received from the bailout in Federal Reserve loans went.
"Was Treasury aware of who the counterparties were that were going to receive payment in full on the credit-default swaps when $170 billion went to AIG?" Warren asked.
"They could have known," Geithner responded. "Whether they knew at the time, I'm not sure they knew."
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AIG revealed the companies that the companies that received payments from AIG were Goldman Sachs, Merrill Lynch, Citigroup, and Bank of America.
The approach in Warren's questioning during this time would largely set the tone for Warren's future feuds with the White House on the premise that it was being too friendly to Wall Street.
Geithner, for his part, did not seem amused by Warren, writing in his memoir, "Her [bailout] oversight hearings often felt more like made-for-YouTube inquisitions than serious inquiries." He called his relationship with Warren "complicated."
Dodd-Frank and the Consumer Financial Protection Bureau
The Consumer Financial Protection Bureau, which was established under Dodd-Frank, is often considered a brainchild of Warren's. But Geithner wrote in his memoir that he believed Warren would face tough Senate opposition to be head of the agency from Republicans and some moderate Democrats wary of Warren. "At a meeting with Rahm and Valerie, I told the group that if the President wanted to appoint Warren to run the CFPB, I wouldn't try to talk him out of it," he wrote "but everyone in the room knew she had no chance of being confirmed."
"They didn't want to vote for a controversial liberal at a conservative moment," he wrote. "They were also worried about the intense opposition in the business community."
Warren faced stiff opposition for CFPB from then-White House Chief of Staff Rahm Emanuel, who informed Sen. Harry Reid that "We don't like her, either," when a moderate Democratic senator said he was concerned about who would head the agency.