Who Will Replace Tim Geithner?

With Tim Geithner apparently stepping down after the debt ceiling showdown, it's worth pondering just who the Obama administration could confirm to replace him. The almost-universal assumption is that the replacement will have to be moderate, or even right-of-center, left the Republicans filibuster his confirmation. Before we work within that assumption, though, it's worth putting some pressure on it. Obama could not appoint a Treasury secretary who is ideologically as liberal as Barack Obama. Someone with Obama's policy preferences could be elected president, but he can't be appointed Treasury Secretary by Obama. Sort of crazy, isn't it?