A provision in the financial reform bill would have allowed Berkshire Hathaway to avoid taking a significant hit - specifically, companies would not be required to hold collateral against existing derivatives trades. Berkshire has a derivatives portfolio of $63 billion, so that's a lot of collateral. The White House and Treasury Department lobbied against the Berkshire provision. With Buffett being an Obama supporter, inserting any grandfather clause would have created major political headaches.