During the impeachment investigation into Donald Trump's conduct with Ukraine, Trump's former national security adviser, John Bolton, refused to testify under oath about his knowledge of Trump's actions.

At the time, Bolton said he needed a subpoena from the House Intelligence Committee to legally compel his testimony — which his lawyer then threatened to fight. After the inquiry concluded and the House voted to impeach, Bolton then said he would be willing to testify during the Senate's impeachment trial. But Republicans blocked the Democratic impeachment managers from calling witnesses, and Bolton never publicly revealed his knowledge of Trump's interactions with Ukraine.

But on Monday, ABC News' Martha Raddatz announced that she sat down with Bolton for an interview in which "no question" was "off limits" — blatantly contradicting Bolton's previous claims that he needed a subpoena in order to publicly reveal any information he possessed about Trump's conduct.

"He's the man the president doesn't want you to hear," Raddatz tweeted, along with a photo showing Bolton speaking to her during an on-camera interview. "I just sat down with John Bolton, Pres. Trump's former trusted adviser, for an exclusive one-on-one interview—with no question off limits.Watch the special event Sunday at 9/8c on ABC."

Bolton has been roundly criticized for his behavior during Trump's impeachment. And those criticisms are once again surfacing as Bolton prepares to publish a tell-all about his time in the Trump administration — which he will be paid at least $2 million for.

"Never forget: At the critical moment, John Bolton chose to make millions for himself instead of serving his country. He now criticizes the Trump presidency. In fact, he personifies everything wrong with it," Rep. Sean Patrick Maloney (D-NY) tweeted on Saturday.

According to Politico, Bolton's book will make serious allegations against Trump, including that Trump committed multiple impeachable offenses similar to the Ukraine scheme.

Trump has tried to block Bolton's book from being published, claiming Bolton included classified material. While Bolton and his publisher have denied the book contains any classified material, they delayed the March release date until June 23 in order to comb through the book one more time and allow the White House to review the manuscript once again before publishing.

The White House is set to return a manuscript with redactions by June 19, four days before the book is slated for publication, the New York Times reported.

It's unclear how much of the book the White House will demand to be redacted. But ABC News reported that the Trump administration may again try and block the release of the book, possibly seeking an injunction from a court on Monday.

"This is a transparent attempt to use national security as a pretext to censor Mr. Bolton, in violation of his constitutional right to speak on matters of the utmost public import," Bolton's lawyer, Chuck Cooper, wrote in a Wall Street Journal op-ed. "This attempt will not succeed, and Mr. Bolton's book will be published June 23."

Democrats say Bolton should've fought this hard when the House sought his testimony during the impeachment inquiry. Trump was impeached for his conduct with Ukraine, but Senate Republicans voted to acquit him.

Rep. Mike Quigley (D-IL), a member of the House Intelligence Committee that led the impeachment inquiry into Trump's conduct, slammed Bolton for speaking freely in a book that will earn him a hefty paycheck but refusing to speak to Congress — where the information could've made a difference in the impeachment proceedings.

"At the time the country needed him most, and history will reflect, he chose to sell books," Quigley told Politico. "It wasn't a question in his mind of whether or not he should talk about it. It's whether or not he should profit from talking about it. Not exactly 'Profiles in Courage.'"

Published with permission of The American Independent Foundation.