Larry Summers advocated for the repeal of provisions of the Banking Act of 1933 that helped to cause the financial crisis of 2008.
Repeal allowed banking organizations to own investment firms and vice versa. Essentially, banks, such as Wachovia and Washington Mutual, poured money into the subprime housing market through these acquisitions which offered loans to those who could not afford them, causing a housing bubble that would burst and ruin the financial lives of millions of Americans.
Larry Summers denies culpability, but without hindsight, much less foresight--especially with his failure to regulate derivatives--he'll make a dangerous Fed chair. Mr. President, Summers is your friend, but please nominate someone else. At the very least, see the film "Inside Job" before deciding.