Republican regulators can share blame with Democratic legislators:
... on April 28, 2004, ... the five members of the Securities and Exchange Commission met in a basement hearing room to consider an urgent plea by the big investment banks.
They wanted an exemption for their brokerage units from an old regulation that limited the amount of debt they could take on. The exemption would unshackle billions of dollars held in reserve as a cushion against losses on their investments. Those funds could then flow up to the parent company, enabling it to invest in the fast-growing but opaque world of mortgage-backed securities; credit derivatives, a form of insurance for bond holders; and other exotic instruments.
The five investment banks led the charge, including Goldman Sachs, which was headed by Henry M. Paulson Jr. Two years later, he left to become Treasury secretary.