President Trump’s impeachment trial opened with a vote to block a subpoena for White House documents related to Democratic allegations the president abused the power of his office by withholding security aid from Ukraine.

The Senate Republican majority defeated a measure 47-53 offered by Minority Leader Chuck Schumer demanding the White House turn over a trove of documents stemming from Trump’s conversations with Ukrainian President Volodymyr Zelensky.

Republicans stayed unified in opposition to the move by Schumer, a New York Democrat.

Republicans instead backed a resolution setting the terms of the impeachment trial that would postpone consideration of additional evidence until after House impeachment managers and Trump’s defense lawyers have presented their cases.

The vote followed arguments by Democratic impeachment managers and the defense lawyers, providing a glimpse of the cases each side will present in the coming days.

The Senate rules allow impeachment managers and the defense lawyers three days each to present arguments.

“The Senate should act on this subpoena now, at the outset of the trial,” Rep. Zoe Lofgren, a California Democrat, argued. “Documents that are directly relevant to evaluating the president’s scheme. If it won’t even ask for this evidence, this trial, and your judgment, will be questioned.”

Trump’s legal team, led by White House counsel Pat Cipollone, argued the House impeachment investigation was partisan, lacked due process, and took shortcuts to speed up the inquiry. The Senate should not be forced to fix the shortcomings of the House impeachment proceedings, Trump’s lawyers argued.

“Never before in the history of our country has a president been confronted with this kind of impeachment proceeding in the House,” Cipollone argued before the Senate.

The House impeachment team, led by Intelligence Committee Chairman Adam Schiff, said the Senate trial, like any trial, should have evidence and witnesses.

Democrats want the Senate to subpoena former national security adviser John Bolton and acting White House chief of staff Mick Mulvaney.

“No trial in America has ever been conducted like that,” Schiff argued. “If you are going to make a decision about whether to remove this president from office, you should want to see what these documents say.”

Schiff called Bolton and Mulvaney to come testify, even though Schiff last year backed off a court fight that may have forced them to testify in the House impeachment proceedings.

“Let’s get this trial started,” Schiff said.