But before Woodward got in the president's crosshairs, the veteran Washington Post reporter who famously covered the Watergate scandal alongside Carl Bernstein was cited favorably, and even defended, on multiple occasions by Trump.
As president, Trump had referred to Woodward in private as someone who has "always been fair," and has publicly cited the reporter in his own defense. Yet in the lead-up to the expose, Trump has gone so far as to suggest Woodward has been an unreliable writer for decades.
Trump's about-face toward Woodward, in spite of his history of compliments for the reporter, provides another stark example of the president's scorched-earth tactic of responding to his critics.
Excerpts from Woodward's forthcoming book, "Fear: Trump in the White House," portray the White House under Trump as chaotic and vindictive, with the president himself frequently undermining his top officials as those same people gripe about him behind his back.
According to the book — which is based on interviews with people who mostly spoke anonymously in order to share their stories freely — Trump called his attorney general, Jeff Sessions, a "traitor," "mentally retarded" and a "dumb southerner"; he said his former chief of staff Reince Priebus was "like a little rat" scurrying around; he mocked ex-national security advisor H.R. McMaster's demeanor and fashion sense, saying he dressed "like a beer salesman"; he told Commerce Secretary Wilbur Ross, "You're past your prime."
The White House has broadly disputed the book as untrue. Press secretary Sarah Huckabee Sanders said, "This book is nothing more than fabricated stories, many by former disgruntled employees, told to make the president look bad."
It also prompted full-throated denials from senior staff members, including current chief of staff John Kelly, who for the second time denied calling the president an "idiot," and Defense Secretary James Mattis, who asserted, "The contemptuous words about the president attributed to me in Woodward's book were never uttered by me or in my presence."
Woodward has said he stands by his reporting.
No one has pushed back against Woodward's forthcoming expose more forcefully than Trump himself, however.
Shortly after the first excerpts from the book were published on Sept. 4, Trump kicked off a stream of Twitter attacks on Woodward and his reporting that continued nearly a week later.
Claiming the book has been "already discredited," Trump floated the possibility that Woodward is a political operative working for Democrats, wondered aloud why lawmakers haven't strengthened libel laws and asserted that he himself will write "the real book" about his White House.
Trump tweet The Woodward book has already been refuted and discredited by General (Secretary of Defense) James Mattis and General (Chief of Staff) John Kelly. Their quotes were made up frauds, a con on the public. Likewise other stories and quotes. Woodward is a Dem operative? Notice timing?
Trump tweet The already discredited Woodward book, so many lies and phony sources, has me calling Jeff Sessions "mentally retarded" and "a dumb southerner." I said NEITHER, never used those terms on anyone, including Jeff, and being a southerner is a GREAT thing. He made this up to divide!
Trump tweet Isn't it a shame that someone can write an article or book, totally make up stories and form a picture of a person that is literally the exact opposite of the fact, and get away with it without retribution or cost. Don't know why Washington politicians don't change libel laws?
Trump tweet The Woodward book is a Joke - just another assault against me, in a barrage of assaults, using now disproven unnamed and anonymous sources. Many have already come forward to say the quotes by them, like the book, are fiction. Dems can't stand losing. I'll write the real book!
Trump tweet The Woodward book is a scam. I don't talk the way I am quoted. If I did I would not have been elected President. These quotes were made up. The author uses every trick in the book to demean and belittle. I wish the people could see the real facts - and our country is doing GREAT!
Yet in a recorded phone conversation with Woodward a month earlier, Trump told Woodward that he "would've loved to have spoken" with the author for the book.
"I'm very open to you. I think you've always been fair," the president said during the call.
This view echoes Trump's previous references to Woodward. In 2013, after Woodward wrote an article for the Post criticizing President Barack Obama for his handling of a political fight over government sequestration, Trump promoted the "must read column by Bob Woodward."
When it was revealed that Obama's economic advisor, Gene Sperling, sent an aggressive warning to Woodward before the column was published, Trump came to Woodward's defense.
"Only the Obama WH can get away with attacking Bob Woodward," Trump said.
During the presidential transition period in January 2017, Trump thanked Woodward for questioning the authenticity of a bombshell dossier alleging salacious and unverified connections between Trump and the Russian government under President Vladimir Putin.
Trump had slammed the document, produced by intelligence firm Fusion GPS and widely scrutinized after it was published by BuzzFeed News, as a "total political witch hunt."
Woodward called the document "garbage" — a statement Trump quickly seized on.
Disclosure: CNBC parent NBCUniversal is a minority investor in BuzzFeed.