Fortunately for the usurper, he (1) didn’t rule in the 20th century, and (2) doesn’t belong on a list of real presidents, just one that’s titled “White House occupants”. Obama would be dead last on any list, ranking well below James Buchanan thanks to his sustained efforts.
If Benedict Arnold had been a President, Soetoro (or whatever his name is) would be below him. If Soetoro, an illegal alien, were actually President.