Speaker Nancy Pelosi (D-Calif.) on Thursday bashed John Bolton as a con artist, saying President Trump's former national security adviser — and now leading Trump critic — threw the country under the bus to sell a book.

Bolton's forthcoming exposé of his 17 months in the Trump White House, details of which were reported Wednesday, takes aim at Trump for being unfit to lead the country. But it also blames House Democrats for taking insufficient steps to remove the president from office.

Pelosi was quick to counter that House Democrats not only impeached Trump in December, but Bolton had refused their requests that he testify in that stage of the impeachment process.

"He was so arrogant in terms of the House when we were engaged in the impeachment," Pelosi said.

If Bolton was so concerned about Trump's threat to the Republic, Pelosi charged, he should have warned Congress at the time instead of reserving those details for his book, which has leapt to the top of best-seller lists even before its release.

"President Trump is clearly ethically unfit and intellectually unprepared to be the president of the United States. That doesn't seem to matter to the Republicans in the United States Senate. It didn't seem to matter to John Bolton," Pelosi said during a press briefing in the Capitol. "He chose loyalty over patriotism. And so he's going to make money off of his book, I guess."

Pelosi left open the possibility that House Democrats will ask Bolton to testify in the coming weeks on the revelations in his book. First, though, she intends to talk to the heads of the committees of jurisdiction, which include the Intelligence, Judiciary, Oversight and Foreign Affairs panels.  

"One thing is for sure: the American people have the right to know," Pelosi said. "Our oversight will always continue. Whether that's by subpoena or some other way, I'll discuss that with the chairs of the committees."

Bolton, a defense hawk with deep roots in conservative national security circles, joined Trump's team in March 2018 as the president's third national security adviser. But the pair clashed over major foreign policy issues — including those related to  North Korea, Iran and Afghanistan — where Trump viewed Bolton's approach as too militant and interventionist.

In September 2019, Bolton submitted his resignation — Trump says he was fired — and began working on the commercial account of his tenure. But Bolton's eyewitness involvement in the most explosive events related to Trump's contacts with Ukrainian leaders made him an attractive witness for House Democrats last fall, when they were conducting their impeachment investigation into that very issue.

Bolton had refused to testify before the House, even under subpoena, citing open legal questions over whether the congressional subpoena outweighs a president's claims to executive privilege, or vice versa. Trump had blocked several subpoenaed witnesses from testifying, invoking executive privilege, and court cases examining that power clash were yet unresolved.

Yet Bolton changed course following the House impeachment vote, offering to testify before the GOP-controlled Senate in the trial stage of the process — if he were subpoenaed.

Senate Democrats sought that subpoena, but it was rejected by the majority Republicans, who expressed little concern that Trump had pressed foreign leaders to help his reelection.

Pelosi said Bolton offered to testify only because he knew Senate Republicans, to protect the president, wouldn't allow him to.

"[He's] trying to keep the con going with the right-wing of the Republican Party by criticizing us for not subpoenaing him when he said he wouldn't come in — he'd only go to the Senate where he knew the Senate would not subpoena him," Pelosi said.

"This is called a con," she added.

In his book, "The Room Where it Happened," Bolton says Trump sought reelection help not only from Ukrainian officials, but from Chinese leaders, as well.

Trump "was pleading with Xi to ensure he'd win," Bolton reportedly writes, referring to Chinese President Xi Jinping.

Rather than criticize Senate Republicans for their refusal to compel his testimony, however, Bolton goes after Pelosi and House Democrats for "impeachment malpractice" in not pursuing a broader investigation.

"If Trump deserved impeachment and conviction, the American public deserved a serious and thorough effort to justify the extraordinary punishment of removing an elected president from office," Bolton wrote. "That did not happen."

Pelosi on Thursday dismissed the critiques, saying Bolton's attacks on Democrats are designed merely to win praise from conservatives — and compel them to buy his new book.

"It's really a sad thing, because he knew that the president should be removed from office, that's clear. And he does want to keep his ties to the right wing, so he does that by criticizing us," she said. "I place no value on that."

Pelosi added that she won't be purchasing "The Room Where it Happened" anytime soon.

"I don't want to spend any money for a book that was a substitute for testifying before Congress about the well-being of the American people," she said. 

Updated at 1:35 p.m.