FDR was a tyrant. Then again he had socialists at the bottom of the country and business leaders a the top trying to over throw him, literally. Millions starving, food shortages, intense racial fighting, etc… He did keep the country together, though. Which the war was tremendous help in that respect. It came at the right time to help him out.
If he did nothing OR some other economic policy. Well, that is not even possible to fathom. Really, your making shit up based on what you want to be true.
Obama, though, is much more like Hoover. A 787 billion dollar unspent stimulus coupled with the banking industry hooked up with an iv to the treasury does not equal a new deal.