Last week, Ron Reagan was shilling for his book by revealing some juicy tidbits about his father; namely, that he was suffering from symptoms of Alzheimer's disease early in his second term.

This, despite the fact that White House doctors - 4 of them - have said that Reagan showed no such symptoms. One might expect that if President Reagan had demonstrated such weakness, one of those four doctors would have written a book on it already. Besides, the idea that those dedicated medical professionals would have allowed someone to remain in office who was mentally impaired just doesn't pass the smell test.

Michael Reagan agrees:

Ronald Reagan's conservative son called his liberal half-brother "an embarrassment" Saturday for speculating in a new memoir that their father suffered from Alzheimer's disease while president.

"Ron, my brother was an embarrassment to his father when he was alive and today he became an embarrassment to his mother," Michael Reagan posted on Twitter.

"My brother seems to want [to] sell out his father to sell books," he added in another tweet.

The sibling tension bubbles over just three weeks before Ronald Reagan's 100th birthday, which will kick off a year of events to honor the 40th president.

Michael Reagan has his own book to sell, but the Reagan Foundation had this to say:

The Ronald Reagan Presidential Foundation, closely tied to former first lady Nancy Reagan, issued its own statement, more delicate but still forceful, pushing back on the claim that he suffered from Alzheimer's while leading the free world.

"We believe Ron has written a wonderfully warm and engaging book about life with his father, Ronald Reagan," the foundation said. "It offers a tribute that only a son could present. As for the topic of Alzheimer's, this subject has been well documented over the years by both President Reagan's personal physicians, physicians who treated him after the diagnosis, as well as those who worked closely with him daily. All are consistent in their view that signs of Alzheimer's did not appear until well after President Reagan left the White House."

Indeed, Reagan was not officially diagnosed with Alzheimer's until 1994. His presidency ended in January 1989.

Little Ron was never satisfied with the attention he got from his father, believing he was slighted because of Ronald Reagan's "distance" from he and his sister Patti. From all reports, Reagan was a loving father who, like many men from his background and age, did not seek to emotionally connect to their children, seeing their role as guide and mentor. It seems strange to us, but this was probably the way that Reagan's own father connected to him. My father's father - a tough Irish immigrant who came over in the 1890's - had that same distance with my dad. if not ideal, it was certainly not out of the ordinary.

What Ron is describing is not Alzheimer's but rather the natural deterioration of the mind that occurs at Reagan's age. The older we get, the harder it is for us to remember things - even simple stuff like phone numbers and addresses. And the hesitancy in Reagan's responses are also the product of the same natural progression of age.

But it is a far cry from even early onset Alzheimer's and Ron Reagan should leave diagnosing to doctors and not seek to sensationalize for the sake of selling his book.