Senators will have another day to pose written questions to House managers and Trumps lawyers when the impeachment trial resumes at 1 p.m. on Thursday.
After that, a crucial vote is anticipated Friday on whether to call witnesses, including Bolton, to testify as part of the trial. In a manuscript of his new book, Bolton reportedly says that Trump directly tied the holdup of nearly $400 million in military assistance to Ukraine to investigations of the Bidens.
A few moderate Republicans have indicated they want to hear from Bolton. Only four Republicans would need to defect and join Democrats in order for a vote to call witnesses to succeed.
McConnell wants to avoid calling additional witnesses, since it could extend the contentious proceedings into unpredictable territory. On Wednesday, leading Republicans were sounding more confident that they would have the votes to avoid witnesses.
Trump is set to deliver his State of the Union address on Tuesday, and Republicans would like to have the impeachment trial behind them by that point. A vote to acquit Trump could come as early as Friday.
During the first question-and-answer session on Wednesday, Trump lawyer Alan Dershowitz argued that presidents could do nearly anything as long as they believe their reelection is in the public interest.
Dershowitzs remarks came in response to a question from Sen. Ted Cruz (R-Tex.) about quid pro quos, one of the offenses Trump is alleged to have committed.
If a president does something which he believes will help him get elected in the public interest, that cannot be the kind of quid pro quo that results in impeachment, asserted Dershowitz, a Harvard Law School emeritus professor.