Nate Silver has a point:
Unless the Washington Post has access to Obama's FICO score -- and unless it has rented an apartment to him, it probably doesn't -- it is missing a pretty important piece of information on what Obama's mortgage rate ought to have been. What was Obama's FICO score? I don't know, but considering that...
* Obama had just gotten a $2.27 million book deal from Random House -- about $1 million more than the value of the mortgage.
* The Obamas each had exceptionally secure jobs that paid them a combined annual salary of about $500,000 per year.
* The Obamas had just sold their condo, on which they had realized a $137,500 profit.
* The Obamas were prominent public figures whose political futures depended in part on maintaining a reputation for responsibility and trustworthiness.
* The Obamas are known to be relatively thrifty and have no credit card debt but substantial savings.
...I would think that the Obamas were exceptionally creditworthy. So indeed, Obama received a "discount" -- the same discount that any borrower in his position would have received.