President Trump unleashed on Paul Ryan in a late-night tweetstorm in response to criticisms the former speaker made in an upcoming book.

In the book, "American Carnage," Ryan recalled his difficult working relationship with the president. He told Politico's Tim Alberta that Trump "didn't know anything about the government" and that he and others "helped to stop him from making bad decisions."

“Because, I’m telling you, he didn’t know anything about government . . . I wanted to scold him all the time," Ryan reportedly said in the book. “Those of us around him really helped to stop him from making bad decisions. All the time. We helped him make much better decisions, which were contrary to kind of what his knee-jerk reaction was. Now I think he’s making some of these knee-jerk reactions.”

Trump blasted Ryan as a "failed" vice presidential candidate with an "atrocious" record of as a congressman.

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"Paul Ryan, the failed V.P. candidate & former Speaker of the House, whose record of achievement was atrocious (except during my first two years as President), ultimately became a long running lame duck failure, leaving his Party in the lurch both as a fundraiser & leader..." Trump tweeted.

Trump went on to claim that when 2012 GOP presidential candidate Mitt Romney chose Ryan as a running mate, he told people "that's the end of this Presidential run."

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"He quit Congress because he didn’t know how to Win," the president continued. "They gave me standing O’s in the Great State of Wisconsin, & booed him off the stage. He promised me the Wall, & failed (happening anyway!)...."

Trump added, "He had the Majority & blew it away with his poor leadership and bad timing. Never knew how to go after the Dems like they go after us. Couldn’t get him out of Congress fast enough!"

This is a drastic shift in tone from the president when Ryan announced he would not be seeking re-election in April 2018.

"Speaker Paul Ryan is a truly good man, and while he will not be seeking re-election, he will leave a legacy of achievement that nobody can question. We are with you Paul!" Trump tweeted at the time.