McCain's new proposal

A McCain surrogate just confirmed to Chris Matthews that McCain's proposal for the government to buy mortgages is in fact new. I wasn't sure, I thought maybe he was just referring to the bailout. How does buying mortgages off people who couldn't afford them and shouldn't have taken them (as he said himself) make economic sense or fit into a conservative agenda? It might be a good idea, it just seems lame to bring it up for the first time in a debate a few weeks before the election. Like it's another...what's that word... stunt.