"Is the president's case so weak that none of the president's men can defend him under oath?" Schumer said on the Senate floor.
President Donald Trump, only the third U.S. president to be impeached, is likely to go on trial in the Senate early in January on the charges related to his attempts to pressure Ukraine to investigate Democratic political foe Joe Biden.
Dismissing the impeachment vote as "toxic" and "slapdash," Senate Majority Leader McConnell made it clear that he did not think the Republican-run Senate would find Trump guilty.
"The vote did not reflect what had been proven.
It only reflects how they feel about the president.
The Senate must put this right," McConnell said on the Senate floor.
McConnell did not elaborate but he has already said he is working in tandem with the White House ahead of a Senate trial, drawing accusations from Democrats that he is ignoring his duty to consider the evidence in an impartial manner.
It was unclear on Thursday how or when a trial in the Senate would play out after House Speaker Nancy Pelosi said she might delay sending over the articles of impeachment to the Senate in order to pressure that chamber to conduct what she viewed as a fair trial.