U.S. President Donald Trump's former National Security Adviser John Bolton said on Monday he is willing to testify in the expected Senate impeachment trial of the president, a surprise development that could potentially strengthen the case that Trump should be removed from office.
As a top White House aide who witnessed many of the events that prompted the House of Representatives to impeach Trump in December, Bolton could provide new evidence about Trump's efforts to pressure Ukraine to investigate Democrat Joe Biden, his potential November presidential opponent.
Other witnesses during the House impeachment investigation testified that Bolton, who was fired by Trump in September, strongly objected to an effort by Trump's personal lawyer, Rudy Giuliani, to pressure Kiev outside of regular diplomatic channels, with one saying he referred to the arrangement as a "drug deal."
Congressional investigators believe Bolton objected to Trump's decision to delay 390 million U.S. dollars in military aid to Ukraine and could elaborate on that, a Senate aide told Reuters.
"Based on careful consideration and study," Bolton said in a statement, "I have concluded that, if the Senate issues a subpoena for my testimony, I am prepared to testify."
Democrats seized on Bolton's announcement, saying it bolstered their argument that he and three current administration officials – White House Chief of Staff Mick Mulvaney, Trump assistant Robert Blair, and budget official Michael Duffey – should testify when the Senate begins its impeachment trial.
"If any Senate Republican opposes issuing subpoenas to the four witnesses and documents we have requested they would make absolutely clear they are participating in a cover-up," Senate Democratic leader Chuck Schumer said.
But the White House claimed executive privilege to prevent the four from testifying before the House. If forced to testify in the Senate trial, Republicans fear they could provide deeply damaging evidence against Trump, raising the risk that he will be convicted and removed from office.
Instead, Republicans are seeking a quick trial based on the evidence collected in the House that could lead to the president's expected acquittal before the 2020 presidential election campaign heats up.
Nancy Pelosi, the Democratic speaker of the House of Representatives, has declined to send the articles of impeachment passed by the House to the Senate until the ground rules have been established for the trial.
Bolton's willingness aside, his subpoena and testimony are not a given. Republicans hold a 53-47 majority in the Senate and most are expected to support Trump in the trial. Issuing a subpoena would require majority support from the senators, meaning several Republicans would have to cross over and join Democrats.
Republican Senator Mitt Romney said he would favor an appearance by Bolton.
"I would like to be able to hear from John Bolton," Romney said. "He has first-hand information and that is something that I'd like to hear."
In his statement, Bolton noted that the constitutional issue of Trump's ability to block his testimony was not resolved in court before the House voted to impeach Trump on December 18.
Even without a court ruling on the issue, Bolton suggested he would be ready to come forward.
In remarks on the Senate floor, Republican Senate Majority Leader Mitch McConnell repeated his proposal that the chamber postpone a decision on whether to call witnesses until after the trial begins.
He denounced the House impeachment inquiry as "unfair" and accused Democrats of political brinkmanship at a time of rising tensions with Iran.
"Even with tensions rising in the Middle East, House Democrats are treating impeachment like a political toy," he said. "At this dangerous time, House Democrats continue to play political games with their partisan impeachment of the commander-in-chief."
Democrats would need four Republicans to side with them to get the majority required to call witnesses.
