Chronicling the explosion of subprime mortgages is a bit like reading Murder on the Orient Express. As in the novel, in which everyone is revealed to have had a hand in the murder, America’s subprime story implicates almost every power centre – including the Bush administration, the Federal Reserve and the Democratic party.

Take Roland Arnall, founder and chief executive of Ameriquest Mortgage Co, the California-based company that made more than $80bn in subprime mortgages between 2005 and 2007.