Ezra Klein has a very interesting graph up (apparently from Larry Bartel's new book) that seems to show "...that income growth during Democratic presidencies is both more progressive -- which is to say, more of it accrues to the poor -- and higher for everyone." He also offers up some quotes from Krugman about being unable to explain mechanism behind this particular phenomenon. I'd love to hear another economist's take on this (Steve - I'm looking at you). Firstly, of course, is it even real? Klein does a pretty reasonable job of hedging his bets about what the appropriate interpretation should be, but I'm wondering about the sources of the data themselves.