Michael Reagan:"my brother was an embarrassment to his father when he was alive and today he became an embarrassment to his mother,”

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. (Full story)

RELATED: Michael Reagan Rips Half-Brother Ron Over Book and Alzheimer's Claim

"I know publishers want to have that 'ah-ha' moment, something to put out to promote the book. But to go to this extent to just tell falsehoods and lies and conspiracy theories to get it out there, is outrageous. Really, to do this to his mother at 89 and as fragile as she can be, Ron and Patti (Davis) are the only two children she's got, and for him to do this just to sell a book, I mean it's just unconscionable. There are enough great stories he could share that would make news, great 'inside baseball' stories."

U.S. News & World Report reported Friday that although Ron, "who became a liberal and atheist, disappointing his dad" writes about presidential brain surgery in San Diego, "there is no reporting about any San Diego operation on Reagan. News reports at the time of his fall say Reagan was flown to a hospital in Arizona, where he was treated for scrapes and bruises and released after five hours." The U.S. News blog Washington Whispers, which first reported the Ron Reagan story, also notes that the president's four White House doctors said they saw no evidence Reagan had Alzheimer's while in office.