From the State Department, he asked for “detailed notes, emails, text and WhatsApp messages, memoranda to file, and diplomatic cables pertinent to the investigation that State Department witnesses told the House are being withheld.” The Office of Management and Budget, he wrote, “is also in possession of highly relevant documents and communications related to this case.”
Democrats including Mr. Schumer said on Sunday that the emails made it all the more urgent that Mr. Duffey and the other witnesses testify.
“If the president is so innocent and claims he’s innocent, why would he not allow, just like Richard Nixon did, the people that were closest to him to testify?” Senator Amy Klobuchar, a Minnesota Democrat who is seeking the presidential nomination, said Sunday on the CBS program “Face the Nation.”
The trial can proceed in one of two ways: Mr. Schumer and Mr. McConnell can reach agreement on a resolution governing the format, or Mr. McConnell can proceed on his own if he can get 51 senators to agree to a resolution.
When President Bill Clinton was tried in 1999, the Senate passed two resolutions. The first, adopted unanimously, governed the basic format of the opening of the trial, including how long each side was given to present its case. The second, which passed along party lines, governed witnesses; there were three, all of whom gave depositions rather than testify in person. Mr. McConnell and other Republicans want Democrats to adopt the Clinton format.
“My belief is that once we’re sworn in, that 51 of us could adopt the rules from last time that would still apply,” Senator Roy Blunt, Republican of Missouri, told reporters Monday in the Capitol.
“The speaker is a powerful position,” Mr. Blunt added. “But it’s not so powerful that the speaker can decide not to follow through on something like this.”
Emily Cochrane contributed reporting.