When he declares war on Iran unprovoked without any justification, then he'll be the worst President in history.
People weren't entirely in agreement with FDR during the Great Depression either, but he must've done something right because America came out of it during his administration (counting Truman).
Similarly, FDR assumed office in a bad position because of the prior administrations failings. If Obama were to take over for Clinton in 2000, we'd be immensely better off than we are now. With all the wealth we had amassed, if it were going to fund the three fields that tend to benefit society and the world at large the most (education, energy, and healthcare) we would be rivaling the Romans at the height of their empire.
Take it for what its worth, Bush screwed up big time, and passed all the problems and unfinished conflicts onto the next guy to solve. While people might not be entirely in agreement with Obama's policies at the time (which I'm not entirely either) if things do get better in the near future, people should be willing to acknowledge his contribution.
All this crap about passing on debt to the future generations is meant to incite fear and anger, in people that know nothing about our current situation. Do you think people really cared about the future generations when they couldn't even afford to eat in the Great Depression? As bad as the debt is (and will be) doing nothing would be like allowing gangrene to grow without amputating. In four years we would be in such a greater world of Sh!t had Obama done nothing.