'I sleep at night': Ex-Trump adviser John Bolton says his testimony would not have changed impeachment outcome

Former national security adviser John Bolton defended his decision not to testify in the impeachment process against President Donald Trump, adding he didn't believe the result would have been any different if he had.

"People can argue about what I should have said and what I should have done," Bolton said Wednesday during a lecture at Vanderbilt University. "I would 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."

During the House impeachment inquiry, Bolton declined to testify voluntarily and vowed to fight a subpoena in court. House Democrats decided not to subpoena Bolton, arguing a lengthy legal battle would render the impeachment – which they said centered on concerns about the integrity of the upcoming election – moot.

Bolton made the remarks alongside Susan Rice, who served as national security adviser under President Barack Obama. Bolton and Rice both also previously served as U.S. ambassadors to the United Nations.

It was Bolton's second public appearance since Trump was acquitted on two articles of impeachment related to allegations he used military aid as leverage to pressure Ukraine into opening politically motivated investigations. According to leaks about the contents of his upcoming book, "The Room Where It Happened: A White House Memoir," Bolton says Trump made it clear that he did not want the aid released until Ukraine agreed to help with the investigations.

Trump has denied telling Bolton or anyone else that the aid was tied to the investigations.