David Fiderer's May 17 post ("GSE Critics Ignore Loan Performance"), suffers from the same logical error that has tripped up all those who try to defend Fannie Mae and Freddie Mac.

There has never been any question that the mortgages Fannie and Freddie acquired to meet their affordable housing quotas were of better quality than the mortgages acquired by private sector securitizers. With subsidized funds, Fannie and Freddie could outbid anyone for the best of the worst.

But although Fannie and Freddie acquired better-quality subprime mortgages than others, the loans they acquired were bad enough to cause these two government-backed firms to become insolvent (which Fiderer conveniently forgets to mention).

As much as Fiderer and others try to defend Fannie and Freddie, and the Department of Housing and Urban Development's affordable housing policies that drove them into insolvency, the taxpayers who bailed them out are unlikely to be fooled.

Peter Wallison is the Arthur F. Burns Fellow in Financial Policy Studies at the American Enterprise Institute.