What really was behind the financial crisis?

This letter to the editor in the Sun is a concise explanation of how the financial crisis occurred. It is simplistic, but lists the most important causes. The writer states that,

The crisis was the ultimate consequence of politicians from both parties pursuing the objective of greater home ownership.

Notice that he blames both political parties. Without the influence of congress, the financial crisis may not have occurred.
He continues,

With a wink and a nod, they let Fannie and Freddie know that the taxpayers would pick up the tab if need be. At the same time, they used the Community Reinvestment Act to coerce the banks into making more subprime loans.

The banks did make risky loans and they did make a profit on them. However, the politicians who encouraged if not actually forced them into this position, are trying to put all the blame on the financial institutions.

If we let them get away with it, shame on us.