In the first presidential debate, Barack Obama did a great job framing the mortgage crisis as one of regulation v. deregulation.
Republicans would be wise to reframe the issue as a question of centralization v. decentralization. FannieMae and FreddieMac were creations of the New Deal which effectively centralized the mortgage industry by giving a tacit understanding that the mortgages were backed by the US taxpayers.
The centralization created this strange thing that unified all of the mortgage markets across the country (and even parts of the world) into one big top heavy market.
The fault of the Republicans is that they failed to realize that centralization is a worse problem than regulation. They were happy to privative the centralized regulatory market; however that market was inherently instable. To make deregulation work, one most completely break the centralized regulatory mechanisms.
Obama's claim is that a regulator jumping up and down on the starboard side of the centralized mortgage market could keep it stable. The truth of the matter is that no markets are ever stable.
Rebuilding the centralized regulatory mechanism might give a moments sense of stability; however, we are just setting ourselves up again for a new crash.
Rather than rebuilding the economy based on tools for a rigid economy. We should realize that markets are fluid and transition our economy from rigid investment tools like mortgages and interest bearing loans to securities that share risks and equity in a fluid market.