by Nicholas Beaudrot of Electoral Math
I'm pretty sure the reason why "conforming mortgage dollar caps have not already been raised substantially" is that George W. Bush is the President. The function of the CEA and NEC under George W. Bush is to act as credentialed mouthpieces for the policy/political goals of George W. Bush, rather than to provide Bush with sound policy advice and then promote said advice in public. In addition, Team Bush, for reasons relating to ideology or interest group brokerage that I simply do not understand, has made constraining the growth of Fannie and Freddie something of a hobbyhorse.
Assuming it's fairly easy to find sixty GOP-held Congressional districts where "do something about the housing mini-meltdown" is a political winner, that leaves the 67th vote in the Senate as the major stumbling block. And I have a hard time figuring out how to get 16 Republicans to vote to force the appropriate agency to raise the mortgage caps on conforming loans. And that's a tall order, when one considers how few Republican Senators represent the states that have had skyrocketing housing values over the last half-decade.