Slight thread drift (perchance) to make a side-point, since the matter came up:

I might point out here just as an aside (ahem!) that polio does not affect one's intelligence or thinking abilities.

FDR's physical disability was no secret to anyone—at the time. The voters knew it and voted for him in great masses. Four times! His political opponents knew it, and it's to their credit that most of them didn't try to make some kind of issue of it, trading on some of the ignorances and prejudices rampant at the time (and still).

It would have been easier for FDR to have used a wheelchair (which he did when not in public), but he was able to walk with leg braces and some assistance. He preferred leaning on someone's arm, usually one of his sons, when walking rather than using crutches or canes when in public. He did this (with considerable effort and discomfort to himself) because he was fully aware that many people were under the impression that having a physical disability meant "weakness" in all areas, including mental, and that would not be acceptable in a political leader. Everyone knew that he'd had polio and he knew that everyone knew (he, after all, was the one who started the "March of Dimes" fund). But using a wheelchair or canes when in public would have been a constant reminder to people, and he wanted them to focus on what he said and did, not on how he walked.

Such ignorance still exists today. Many times when my wife and I are out somewhere (me in my wheelchair), people (who don't know me) will talk to my wife, speaking of me in the third person, even though I am right there. "Would your husband care for a cup of coffee?" To which Barbara will respond (with a bit of heat), "Why don't you ask him?" (On those occasions, I often turn on my radio announcer voice.).

Roosevelt contracted poliomyelitis at the age of 39, although there are some medical men who now think that he may have had Guillain-Barré syndrome rather than polio. The effect on motor nerves is essentially the same, so if it was indeed a misdiagnosis, it's understandable due to the similarity of symptoms.

On the morning of April 12th, 1945, he complained of having "a terrific headache," and died of a massive cerebral hemorrhage (stroke) shortly thereafter. This was unrelated to his post-polio (or GBS).   He had recently returned from the Yalta Conference, had addressed Congress about the conference on March 1st, where it was noted that he looked very thin and drawn. It was also noted that, despite his appearance, he was as mentally sharp and eloquent as he ever was. He had been planning to go to San Francisco to attend the founding meetings of the United Nations when he died.

Reagan was a halfway decent actor (but no Lawrence Olivier). As a politician, he seemed to have a great deal of charisma, but he was not a deep-thinker by any means. To me, the "Great Communicator" spoke mostly in bumper-stickers. Quotable stuff, but pretty shallow. I don't know how—or if—his later Alzheimer's Disease may have effected his mental processes while President.

Bush strikes me as incredibly "average." Downright mediocre, in fact. An average student in school (goof-off and party animal), a gold-brick in the Texas and Alabama Air National Guards (although it was said of him that he was quite a good pilot, whenever he bothered to show up). As an oil man (his father bought him the business) he managed to drive the company into bankruptcy, and one of his first acts as owner of the Texas Rangers (daddy bought him that, too) he traded Sammy Sosa (record-breaking home run hitter) to the Chicago White Sox.

The only things Bush had going for him were name recognition and that he could be led. Had to be led. By people like Cheney.

It is said of George W. Bush that his father also bought him the Presidency. And he broke that, too!

Don Firth