Yes, the current Republican line was that Fannie and Freddie caused the entire problem. Of course people who are not complete idiots note that Fannie and Freddie were bailed out weeks ago and the problem persists. In fact the problems grow more and more extensive and expensive. So obviously some people in other high places made a lot of bad decisions.
Fannie and Freddie did not hold a gun to Country Wide's or WaMu's heads and force them to make bad loans. They did not create those insane derivatives or force the bond rating agencies to commit fraud. Phil Gramm opened the way for the derivatives and Bush told the regulators to look the other way.
Would more regulation on Freddie and Fanny have made a difference?
I doubt it.