But Pelosi threw a curveball into the timeline for the Senate trial by refusing to say when, or if, she would send over the articles, a first step to starting the proceeding in the upper chamber. Democrats say they are waiting for more details on what the trial will look like before they appoint House managers.

"Mr. Trump if you believe you've done nothing wrong, you have nothing to be afraid of from witnesses and documents," Schumer said on Tuesday. "If my Republican colleagues believe the president has done nothing wrong, they should have nothing to fear."

But McConnell wants two resolutions. The first, passed at the outset, would deal specifically with the procedures for a trial. A second resolution, passed after opening arguments from both sides and questions from senators, would determine which, if any, witnesses are called.

With a larger deal between McConnell and Schumer unlikely, 51 senators will effectively be able to determine the process for the trial. McConnell appears to have the votes to establish the rules and punt a decision on witnesses until after the trial starts.