Well, it is interesting, but everyone's opinions and feelings differ on this and they're all somewhat subjective. I think that the Presidents of the far past had a weaker magnifying glass on them (maybe not at the time, but via the "Retrospectoscope") compared to the more recent ones.
Also, I think circumstances can make or break one...and the perceptions of the people of that time. Clearly some were outstanding in how they 'rose' to the challenges, but not all of them had major challenges to rise to.
JMO.
