Former President George H.W. Bush and son George W. Bush have some harsh words for President Trump in a new book coming out.

Trump is "a blowhard," says the elder Bush in the upcoming book, "The Last Republicans," by historian Mark Updegrove.

George W. Bush said of his Republican successor: "This guy doesn't know what it means to be president."

The quotes come Saturday from CNN and the New York Times, both of which spoke to Updegrove.

The title of the book was inspired by a quote George W. Bush made during the 2016 campaign: ā€œIā€™m worried that I will be the last Republican president.ā€

Updegrove said the animosity coming from the Bush family "makes perfect sense."

"If you look at the Bush family, it makes perfect sense. Donald Trump is everything that the Bush family is not," Updegrove told CNN. "George Bush grew up thinking about the greater good. Donald Trump is manifestly narcissistic. It's part of his brand. And that brand is the antithesis of the Bush brand."

His book is scheduled to be published Nov. 14 by HarperCollins.

Tension between the Bushes and Trump have long been documented. Neither Bush endorsed Trump during the 2016 campaign in which Trump mocked George W. Bush's brother, Jeb Bush, who ran an unsuccessful campaign for the GOP nomination, with such phrases as "low energy."

It was reported that George W. Bush and wife Laura Bush didn't vote for Trump or his Democratic rival, Hillary Clinton. They attended the Trump inauguration on Jan. 20; however, the elder Bush did not, citing health complications.

George W. Bush spoke at an event in New York last month, where he offered an implicit rebuke of Trump. He said "bigotry seems emboldened" and of "nationalism distorted into nativism." He never said Trump's name, but many politicos and journalists made the inference.

George H.W. Bush revealed to Updegrove that he voted for Clinton.