While Congress debated the White House's proposal for a $700 billion banking rescue, the U.S. Treasury quietly changed tax policy that resulted in a $140 billion windfall for American banks. Lawmakers did not immediately notice the sweeping change made to more than 20 years of tax policy, but some were furious when the change came to light. "Did the Treasury Department have the authority to do this? I think almost every tax expert would agree that the answer is no," said George K. Yin, the Joint Committee on Taxation's former chief of staff. "They basically repealed a 22-year-old law that Congress passed as a backdoor way of providing aid to banks."