There is a particular focus on John Bolton, who was described by other witnesses as adamantly opposed to any delay in the release of military aid to Ukraine. At one point Bolton reportedly described Trump's efforts to obtain political assistance from Ukraine as a "drug deal."
Bolton unexpectedly announced January 6 that he would be willing to testify before the Senate if he were subpoenaed. He refused to testify voluntarily before the House, and the House Intelligence Committee decided not to issue a subpoena after Bolton's lawyer suggested he would fight it in court.
President Trump declared Friday that he would invoke executive privilege to block Bolton's testimony in the event the Senate decided to subpoena him. He claimed this was not because Bolton's testimony would be damaging, but to preserve confidentiality "for the sake of the office."
Several Republican senators considered to be possible defectors on a procedural vote, including Susan Collins of Maine and Mitt Romney of Utah, have expressed interest in having Bolton testify at the trial.
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