A ton of finger pointing has been done, and a lot of people seem to think that it's Bush's fault. I tend to disagree, after all, I think everybody agrees that the housing bubble started this economic downturn and it was the GSEs that was it’s keystone. This is a interesting montage of a discussion in 2004. Check out the key players that are defending those practices.
Here's a great video to show you exactly who was on what side of the debate back in 2004, when things were great.