Tulsi Gabbard, the former Democratic congresswoman, has repeated a discredited claim about Hillary Clinton that previously saw Gabbard lodge then drop a $50m defamation suit in a new book published as she seeks to be named Donald Trump’s running mate for US president.

Accusing Democrats of making up “a conspiracy theory that [Trump] was ‘colluding’ with the Russians to win the election” in 2016, Gabbard claims: “Hillary Clinton used a similar tactic against me when I ran for president in 2020, accusing me of being ‘groomed by the Russians’.”

Gabbard ran for the Democratic nomination. Clinton did not accuse her of being “groomed by the Russians”.

What Clinton said, in October 2019 and on a podcast hosted by the former Barack Obama adviser David Plouffe, was that she thought Republicans would encourage a third-party bid in 2020, aiming to syphon votes from the Democratic candidate in key states as Jill Stein, the Green candidate, and the Libertarian, Gary Johnson, did four years before.

“They are also going to do third-party again,” Clinton said, “and I’m not making any predictions but I think they’ve got their eye on somebody who is currently in the Democratic primary and are grooming her to be the third-party candidate.”

Gabbard was then in the Democratic primary, though she never made any impact.

Clinton continued: “She is a favorite of the Russians. They have a bunch of sites and bots and other ways of supporting her so far. And, that’s assuming Jill Stein will give it up, which she might not because she’s also a Russian asset. Yeah, she’s a Russian asset. Totally. And so they know they can’t win without a third-party candidate. I don’t know who it’s going to be, but I will guarantee they’ll have a vigorous third-party challenge in the key states that they most need it.”

Amid uproar, a spokesperson for Clinton said she had been referring to Gabbard and the Russians – saying “If the nesting doll fits”, thereby stoking media coverage in which Clinton’s remarks about “grooming” and “assets” were conflated.

Clinton’s meaning was soon cleared up, but Gabbard seized on the “grooming” remark. She penned an op ed in the Wall Street Journal under a headline, I Can Defeat Trump and the Clinton Doctrine, that might now prove an awkward fit with her political ambitions.

Later, after dropping out of the Democratic primary and endorsing Joe Biden, who she said had “a good heart” and would “help heal” a badly divided country, Gabbard sued Clinton for $50m over the “Russian asset” comment, rather than the remark about “grooming”. That lawsuit was dropped in May 2020.

Four years on, Gabbard has completed a remarkable journey across the political aisle, from being seen as a rising Democratic star in the US House to hosting on Fox News and speaking at events including CPAC, a hard-right annual conference. Her book – For Love of Country: Why I Left the Democratic Party – will be published next week. The Guardian obtained a copy.

On the page, Gabbard presents a mix of memoir – from growing up in Hawaii to service in Iraq, from entering Congress to her failed presidential run – and pro-Trump screed. Light on detail and heavy on invective, the book includes excoriations of US support for Ukraine in its war with Russia. It will hit shops, however, in the aftermath of the passage in Congress of billions of dollars in new Ukraine aid.

Gabbard is widely reported to be a contender for Trump’s running mate in his rematch with Biden. In her book, she defends the 88-times criminally charged former president on many legal fronts.

Her complaint about Clinton’s remarks about Russia seems designed to stir up familiar Trump campaign furies over Clinton and the investigation of Russian election interference in 2016, which US intelligence agreed was carried out in his support but which prompts Gabbard to write: “None of it was true.”

She also accuses Democrats of planting evidence and stories with a compliant press, aided by a “deep state” consisting of “active and retired officials from within the justice department and other national security agencies”.

The deep state conspiracy theory, which holds that a permanent government of operatives and bureaucrats exists to thwart populist leaders, is popular with Trump and followers notably including Liz Truss, a former UK prime minister. However, one of its chief creators and propagators, the Trump aide and ally Steve Bannon, has said it is “for nut cases”.

Gabbard does not only repeat conspiracy theories in her book, but also makes elementary mistakes. In rehashing her inaccurate complaint about Clinton saying she was being “groomed” by Russia, she writes that Clinton was speaking to David Axelrod, also a former Obama advisor but the host of a separate podcast to Plouffe’s.

Gabbard also claims that “the propaganda media repeated Clinton’s lies over and over, without ever asking for evidence or fact-checking her themselves”.

In fact, Gabbard’s claims against Clinton were widely fact-checked or made the subject of article corrections.

In October 2019 – months before Gabbard filed suit – the Washington Post, a leading exponent of the fact-checking form, said: “The initial news reports got it wrong, perhaps fueled by the ‘nesting doll’ comment, with many saying Clinton said the Russians were grooming Gabbard for a third-party bid.”

Clinton, the paper added, “certainly said Gabbard was backed by Russian bots and even suggested she was a Russian asset”. But “within a 24-hour news cycle, Clinton’s staff made it clear she was talking about the GOP, not the Russians, eyeing Gabbard as a possible third-party candidate. A simple listen to the podcast confirmed that.

“In other words, this was all cleared up 12 days before Gabbard published her [Wall Street Journal] article, making the inaccurate version of [the] ‘grooming’ statement the very first sentence. So there’s little excuse for getting this wrong.”

The paper therefore awarded Gabbard three Pinocchios – denoting “significant factual error and/or obvious contradictions” – out of a possible four.