Barbara Bush hated Donald Trump so much that she kept a 'countdown clock' in her bedroom, ticking off the seconds until he would leave office.

The former first lady died in April 2018 at the age of 92. Her husband, former President George H.W. Bush, passed away seven months later.

She blamed the current president for a flare-up of her congenital cardiac condition, a moment she thought was a heart attack at the time, according to a forthcoming book by USA Today reporter Susan Page.

And Mrs. Bush was so bothered by the brand of Republicanism Trump brought to the house where she once lived for four years that she had a hard time identifying with the GOP.

Former first lady Barbara Bush hated Donald Trump so much that she kept a countdown clock by her bed, tracking the seconds until his first term was over

A friend in Kennebunkport, Maine gave her a clock like this one, according to a new book about the Bush matriarch, and she liked it so much she brought it with her when she moved back to Houston

President Donald Trump's slash-and-burn style bothered Mrs. Bush to the point where it alienated her from the Republican Party

Asked last year if she still considered herself a Republican, she replied: 'I'd probably say no today.'

She couldn't bring herself to vote for either Donald Trump or Hillary Clinton in 2016. She wrote in her son Jeb's name instead.

USA Today journalist Susan Page's book 'The Matriarch' will hit stores in April

And that countdown clock was by her bedside when she died.

'After Trump was elected, a friend in Kennebunkport gave her a Trump countdown clock as a joke,' Page writes in 'The Matriarch,' which goes on sale April 2. 'The red, white, and blue digital clock displayed how many days, hours, minutes and seconds remained in Trump’s term.'

'She liked the countdown clock so much that when the Bushes returned to Houston that October, she brought it with her. It sat on her bedside table, where she could see it every day. It was there to the day she died. '

But ultimately, Mrs. Bush was hopeful that the U.S. would survive what she saw as a painfully disruptive episode that turned the presidency on its ear.

'I'm trying not to think about it,' she said, nearly a year after Trump took office.

'We're a strong country, and I think it will all work out.'

In this Aug. 24, 1992, file photo, President George H.W. Bush and first lady Barbara Bush walked with their dog Millie across the South Lawn as they returned to the White House

Page recalled her 2016 pronouncement after Trump ridiculed Jeb for deploying her to campaign for him during the New Hampshire Primary season.

'Just watched Jeb’s ad where he desperately needed mommy to help him,' Trump had tweeted. 'Jeb—mom cannot help you with ISIS, the Chinese or with Putin.'

'Putin endorsed him, for heaven’s sake,' Mrs. Bush erupted. 'Putin the killer! Putin the worst! He endorsed Trump! That’s an endorsement you don’t want.'

After her death, the thrice-married Trump took a moment during a press conference with Japanese Prime Minister Shinzo Abe to quip: 'Melania and I send our prayers to Barbara’s husband of 73 years. I’ll never beat that record.'