Explaining his decision to publish tapes of his 20 interviews with Donald Trump, renowned journalist Bob Woodward said he had finally recognized the “unparalleled danger” the former president poses to American democracy.

His three books on the Trump presidency, Woodward said, “didn’t go far enough”.

The veteran reporter will release an audiobook, The Trump Tapes, on Tuesday. On Sunday, he published excerpts in an essay for the Washington Post, the paper for which he and Carl Bernstein covered the Watergate scandal that brought down Richard Nixon’s presidency in 1974.

Woodward, 79, has chronicled every president since. His three Trump books – Fear, Rage and Peril, the last written with Robert Costa – were instant bestsellers.

But by Woodward’s own admission, those books exercised reportorial caution when it came to passing judgment, even as they chronicled four chaotic years culminating in the January 6 Capitol attack.

Woodward’s decision to pass judgment now did not meet with universal praise.

Oliver Willis, a writer for the American Independent, a progressive outlet, pointed to recent criticism of reporters including Maggie Haberman of the New York Times, for allegedly holding important reporting for Trump books. Willis said Woodward essentially saying “Guys, I’m kind of feeling Trump might be a fascist” was a “perfect example of how ivory tower journalism fails to inform the public”.

Seth Abramson, the author of three books on Trump, said: “I don’t know how it happened, but the Trump biographers who knew this for certain because of their research in 2016 and 2017 were outsold by Bob Woodward 10-to-1 despite him only coming to this conclusion now. A failure of media, or of publishing? Or both?”

In the Post, Woodward elaborated on his change of mind.

“There is no turning back for American politics,” he wrote. “Trump was and still is a huge force and indelible presence, with the most powerful political machine in the country. He has the largest group of followers, loyalists and fundraisers, exceeding that of even President [Joe] Biden.

“In 2020, I ended Rage with the following sentence: ‘When his performance as president is taken in its entirety, I can only reach one conclusion: Trump is the wrong man for the job.’

“Two years later, I realize I didn’t go far enough. Trump is an unparalleled danger. When you listen to him on the range of issues from foreign policy to the [coronavirus] to racial injustice, it’s clear he did not know what to do. Trump was overwhelmed by the job.”

In June 2020, Woodward said, he asked Trump if he had assistance in writing a speech about law and order amid national protests for racial justice.

Trump said: “I get people, they come up with ideas. But the ideas are mine, Bob. Want to know something? Everything is mine.”

Woodward wrote: “The voice, almost whispering and intimate, is so revealing. I believe that is Trump’s view of the presidency. Everything is mine. The presidency is mine. It is still mine. The only view that matters is mine.

“The Trump Tapes leaves no doubt that after four years in the presidency, Trump has learned where the levers of power are, and full control means installing absolute loyalists in key cabinet and White House posts.

“The record now shows that Trump has led – and continues to lead – a seditious conspiracy to overturn the 2020 election, which in effect is an effort to destroy democracy.

“Trump reminds how easy it is to break things you do not understand – democracy and the presidency.”

Leftwing writers were not uniformly skeptical of Woodward’s motives. At the New Republic, Michael Tomasky said he hoped the tapes might influence voters in the looming midterm elections, in which a Republican party firmly in Trump’s grip is poised to take the House and perhaps the Senate.

Tomasky wrote: “I hope against hope that the media frenzy that will attend this release will bring Trump back into focus as an issue in this election. There may be nuclear bombshells buried in the tapes that have been held back from the selective leaks.

“One wonders whether Woodward is holding some newsy quotes until Tuesday.”

Tomasky added: “Let’s hope so, anyway, because what has been striking in these recent weeks is the extent to which Trump has faded from the electoral conversation.”

Republicans aiming to take House and Senate seats, governors’ mansions and important state posts will hope things stay that way.

Trump is in legal jeopardy on numerous fronts, from investigations of the Capitol attack and attempts to overturn the 2020 election to a legal fight over his retention of White House records, criminal and civil suits concerning his business activities, and a defamation suit from the writer E Jean Carroll, who says Trump raped her.

The former president denies wrongdoing and continues to float a third White House run. On Sunday, Woodward told CBS he regretted not pressing Trump about whether he would leave the White House if he lost in 2020.

On the relevant tape, Woodward says: “Everyone says Trump is going to stay in the White House if it’s contested. Have you thought …”

Trump interjects: “Well, I’m not – I don’t want to even comment on that, Bob. I don’t want to comment on that at this time. Hey Bob, I got all these people, I’ll talk to you later on tonight!”

Woodward said: “It’s the only time he had no comment. And this, of course, was months before his loss. And I kind of slapped myself a little bit: Why didn’t I follow up on that a little bit more?”

• This article was amended on 24 October 2022 to correct a misspelling of Oliver Willis’s surname.