On Tuesday, Senate Majority Leader Mitch McConnell (R-KY) threw cold water on Senate Minority Leader Chuck Schumer’s (D-NY) request to subpoena crucial witnesses for the Senate’s impeachment trial of President Donald Trump.

“The Senate is meant to act as judge and jury to hear a trial, not to rerun the entire fact-finding investigation because angry partisans rushed sloppily through it,” McConnell said on the Senate floor.

The GOP Senate leader argued that agreeing to Schumer’s proposal would set a “nightmarish precedent for our institution.”

“If the Senate volunteers ourselves to do House Democrats’ homework for them, we will only incentivize an endless strain of dubious partisan impeachments in the future,” McConnell said. “And we will invite future Houses to paralyze future Senates with frivolous impeachments at will.”

Schumer had sent McConnell a letter on Sunday asking him to subpoena acting Chief of Staff Mick Mulvaney and his top assistant, Robert Blair, along with former National Security Adviser John Bolton and Office of Management and Budget official Michael Duffy. All four men were central figures in Trump’s Ukraine scheme who refused to show up for their House impeachment hearings.

The Democratic leader made the request in response to McConnell’s unabashed declaration that he was coordinating with White House lawyers to navigate the impeachment trial in Trump’s favor.

McConnell rejects Schumer’s request for witnesses at the Senate impeachment trial, arguing that the Senate would be doing House Democrats’ “homework for them.” pic.twitter.com/ygVzOmxkbU — TPM Livewire (@TPMLiveWire) December 17, 2019

Schumer slammed McConnell’s rejection shortly after the Republican lawmaker’s speech on Tuesday.

“I still expect we’ll sit down and discuss trial parameters despite his public appearances on Fox News,” the Democrat said. “But let me say this: I listened to the leader’s speech. I did not hear a single sentence, a single argument, as to why the witnesses I suggested should not give testimony.”

Schumer said his GOP colleague’s refusal to call the four men to testify was an “aberration.”

“Why is the leader, why is the President, so afraid of having these witnesses come testify?” he asked. “What are they afraid the witnesses would say?”