I just read an interesting article in the
New York Times about all four people running for executive positions in the upcoming election providing limited health reports. In Barack Obama's case a one page letter from his personal doctor was provided stating that he is in "excellent" condition, but has holes considering his history with smoking, mother's cancer and father's drinking problem. McCain's report was given in 1200 pages, but is obscure about where his condition will lead. Joe Biden provided a report regarding his 1988 aneurysms and the fact that he recovered completely, but info is still inconclusive. And Sarah Palin has not provided anything. None of the candidates' doctors have granted interviews.
Here's my take on all the secrecy:
Barack Obama:Theory one: Obama is the savior so there's no need to pry further. He will remain in perfect health until the end of the world. He just doesn't want to cause a stir. A blood test made public would reveal his true identity.

Theory two: Obama comes from another planet. A blood test proving him to not be human would definitely cause a stir. If McCain supporters think he's a Muslim or an Arab and they have a problem with that then finding out he's an extraterrestrial would be a holiday for them.
Theory four: Obama is from Atlantis. Checking for webbed feet and gills would surely give the right wing conservatives a field day.
Joseph BidenTheory one: His miraculous full recovery is due to being healed by Barack Obama.

Theory two: His dad always told him - "If someone knocks you down, GET UP". So from that day on he attained powers to "get up" under the most extreme health challenges. A conclusive blood test proving his super hero status would surely cause a stir.
Theory three: He grew up in Scranton. Irrelevant yet effective.
John McCainTheory one: McCain has made a pact with the devil. He's been granted longevity despite his ailing appearance.

Theory two: He is Frankenstein's monster.
Theory three: Un-dead.
Sarah PalinTheory one: Palin pulled a Bree Hodge with Trig after Bristol became preggers with her first child. Doctor's records might reveal this.

Theory two: Palin is an evil sea monster.