Former National Security Advisor John Bolton admitted Wednesday that his testimony in President Donald Trump’s recent impeachment proceedings involving Ukraine would have had no impact on the trial’s outcome even after sections of his upcoming book leaked attempting to convict the president in its final days.

“People can argue about what I should have said and what I should have done,” Bolton said at Vanderbilt University Wednesday night during a forum with his predecessor Susan Rice, according to ABC News. “I will bet you a dollar right here and now my testimony would have made no difference to the ultimate outcome.”

“I sleep at night because I have followed my conscience,” Bolton added.

Rice challenged Bolton’s decision to remain silent throughout the process despite not ever being subpoenaed by the House or Senate in the proceedings.

“It’s inconceivable to me that if I had firsthand knowledge of a gross abuse of presidential power, that I would withhold my testimony,” Rice said. “I would feel like I was shamefully violating my oath that I took to support and defend the Constitution.”

Bolton argued that the House botched the process and condemned House Democrats for having committed “impeachment malpractice.”

“The process drove Republicans who might have voted for impeachment away from the president because it was so partisan,” Bolton claimed.

Bolton’s new book, “The Room Where It Happened: A White House Memoir,” is slated to be released next month is expected to reveal what Bolton might have said had he been forced to testify before lawmakers in the impeachment proceedings. Republicans in the Senate defeated Democrats’ efforts to bring Bolton before the upper chamber before the final vote with only Sens. Mitt Romney of Utah and Susan Collins of Maine voting in favor of the measure.

In the final days of the trial however, sections of Bolton’s upcoming book were leaked to the New York Times, featuring Bolton accusing Trump of tying the nearly $400 million in military aid to Ukraine with politically motivated investigations as Democrats alleged. The leak happened to come on the same day the book became available for online pre-order revealing the move as nothing more than a publicity stunt.

On Monday, Bolton accused the White House of trying to suppress details in the book in his first public remarks since the president’s exoneration at Duke University.