Everyone seems to think...

...Joe Biden is running for president. But on election day, 2016, the vice president would be almost 74 years old. And if he served two full terms, Biden would leave the Oval Office at age 82.

Ronald Reagan, in comparison, was the oldest president inaugurated, at age 70. And the Gipper, who was diagnosed with Alzheimer's disease at age 83, was 77 when he left office.

According to Wikipedia, "All four of Reagan's White House doctors said that they saw no evidence of Alzheimer's while he was president."

But Dr. Lawrence K. Altman, a physician employed as a reporter for the New York Times, noted that "the line between mere forgetfulness and the beginning of Alzheimer's can be fuzzy."

Finally, Dr. John E. Hutton, Reagan's primary physician from 1984 to 1989, said the president "absolutely" did not "show any signs of dementia or Alzheimer's."

(If you have to deny something that much, it has to make people wonder.)

So Joe Biden, in 2016, would be the oldest president to assume the office in U.S. history. That's a little hard to picture, isn't it?