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During President Trump's impeachment trial on Thursday, Sen. Lisa Murkowski (R-Alaska) brought up the issue of witnesses, asking Trump's defense team, "Why should this body not call Ambassador Bolton?"


Former National Security Adviser John Bolton reportedly writes in his forthcoming book that Trump spoke to him about withholding military aid from Ukraine until leaders there investigated his political rivals. This directly contradicts Trump, who has claimed there was no quid pro quo.

Patrick Philbin, a deputy White House counsel, responded by saying the House should have had Bolton testify during the impeachment inquiry, but did not send him a subpoena. If he is called as a witness now, it would "do great damage" to the Senate because "whatever is accepted in this case becomes the new normal for every impeachment proceeding in the future." The House asked Bolton to testify, but he declined after being instructed to do so by the White House.

Democrats need four Republicans to vote with them in order to call witnesses, and Murkowski has indicated she is open to hearing from Bolton.