You can if the Imperial Wizard of the Ku Klux Klan is calling it, but I'll be reasonable and take what you said as completely right like you are 110% of the time.
So because Obama is younger and the probabilities of him not dying are better than McCains I should vote him president?
Also considering modern medicine is making it so that many people live a century; I'm pretty sure a 72 year old that beat skin cancer will make it another 4 years hell i'll even say he'll make it another 8.
Also McCain is in phenomal shape, for a 72 year old to only take an aspirin, an occasional zyrtec and ambien to go to sleep when traveling is remarkable I have patients at the age of 45 that take 13 different pills for things ranging from low bone density to high blood pressure.
http://www.cnn.com/2008/HEALTH/05/23/mccain.health.records/index.html