Dan, Greenspan is certainly right that the Fed would have had a whole lot of trouble resisting the immense pressure politicians of both parties exerted to try to increase home ownership.
In the latest National Affairs, the historian Vincent Cannato lays out the story of a century of intense government efforts to increase home ownership which, as he says, did a lot of good but also a lot of harm, and became detached from economic realities in the past couple of decades.