So who's the real dunce?
We can draw a few conclusions from this data set, subject to the various usual problems with studies like this, which rely heavily on analysis of subjective interpretations rather than objective facts.
Ronald Reagan man apparently had an IQ of no more than 140- already making him an extremely intelligent man. While few would deny that his predecessor, President Carter, had greater raw intelligence, President Carter was nothing short of a catastrophe, while President Reagan became a legend in his own lifetime.
And let it be remembered that we don't actually know what Barack Obama's IQ is, because he has gone to extraordinary lengths to hide his school and university records from the rest of us. Be it noted, though, that the best estimates we can come up with indicate that his IQ is probably somewhere between 115 and 130.
That, by the way, makes him a very strong contender for the dumbest man ever to occupy the Oval Office.
If you have been paying attention to his public appearances and off-the-cuff speeches for the last 7-odd years, this will come as precisely no surprise.