In a letter to Senate Majority Leader Mitch McConnell on Sunday evening, Minority Leader Chuck Schumer said that Senate Democrats are requesting testimony from four administration witnesses, including acting chief of staff Mick Mulvaney and former national security advisor John Bolton. The move from the Senate Republicans would be unlikely, unless approved by the White House. Schumer said he hoped that he and McConnell could unite in helping the Senate “rise to this critically important occasion.” The Democratic senator also asked that the Senate trial process begin on Jan. 6 with the actual trial commencing on Jan. 9—an event that will determine whether senators will convict the president on high crimes and misdemeanors. If they do, Trump would be removed from office. The House is expected to impeach the president this week. “The trial must be one that not only hears all of the evidence and adjudicates the case fairly; it must also pass the fairness test with the American people,” Schumer wrote in the letter, adding, “That is the great challenge for the Senate in the coming weeks.” 

Doug Andres, a spokesman for McConnell, said that the senator has planned to meet with Schumer to “discuss the contours of a trial” and reach a deal that could garner bipartisan support. The senators have disagreed on an approach to call witnesses, namely Trump’s request to invite former vice president Joe Biden and his son, Hunter, which Schumer has adamantly resisted. Senate Republicans have decided on a strategy that involves hearing from Trump and House Democrats and subsequently calling witnesses, while Schumer says all witnesses, documents, and trial parameters “should be considered in one resolution.”