Senate Majority Leader Mitch McConnell said in a private meeting on Tuesday that Republican leaders do not currently have enough votes to block impeachment witnesses, according to The Wall Street Journal. Sources cited by the Journal said McConnell made the remarks in a private Senate GOP meeting where he appeared to have a running tally of the votes. The Republicans had hoped to conclude the trial with an acquittal for President Trump this week, but Democrats have been pushing to subpoena individuals and materials to gather more information on Trump's alleged pressure campaign in Ukraine. Explosive excerpts from former national security adviser John Bolton's book that have leaked in the media, along with Bolton's stated willingness to testify if subpoenaed, have also raised concerns about moving the trial to a vote before calling more witnesses.

The vote is not expected until Friday. According to The Washington Post, several senators running in 2020 said they were ready to move on to the final vote and “move on from the trial.”