For Obama, the worst economy for an incoming president since...
drum roll, please....
Ronald Reagan-- and probably by a good margin.
By all of the indicators in economics and foreign policy, Reagan inherited a much worse situation:
-In the macro-economy, unemployment as well as double-digit inflation, interest rates above 20%, and the last time we had a significant trade surplus in goods & services (and thus, an investment deficit-- indicating that people didn't want to invest here vs. the rest of the world).
-In foreign policy, there was the Iranian hostage crisis for something short-term, the ever-dangerous Soviets for the longer-run, and yes, the Israeli/Palestinian conflict for the just-short-of-eternal-run.
-In attitude, we were in the midst of what Carter famously called "malaise".
The only potential, significant counter-example are the unknowns created by the possibilities of a continuing financial crisis. Only time will tell if greed and bail-outs will have an even larger "pay-out" for the population at large.
Why is Obama taking the comparison back to FDR? Historical ignorance? Perhaps. Wanting to connect himself to a Democrat rather than a Republican? Perhaps, but that would be odd for someone who purports to be post-partisan. More likely, it's useful for rhetorical purposes-- both to "change" expectations, impact the way we'll likely see him in future history, and to make us more willing to embrace dramatic reforms.
The problem is it's not true.