(CNN) -- House impeachment managers begin making their case for removing President Donald Trump from office on Wednesday following a marathon opening session in the Senate's impeachment trial to approve the rules of the trial.
On Tuesday and into the early morning hours Wednesday, Republicans repeatedly rejected motions to subpoena witnesses and documents related to the President's Ukraine scandal. Now the House Democratic managers will have 24 hours, spread out over three days, to try to convince Senate Republicans that the trial should seek additional materials and testimony.
The lengthy debate that came after Senate Minority Leader Chuck Schumer offered 11 amendments to the Senate Republican rules resolution did little to convince rank-and-file Republican senators that they should change course. Several Republican senators on Wednesday echoed Senate Majority Leader Mitch McConnell in arguing against having witnesses for the trial after each side makes its presentations and the senators have a chance to ask questions.
"Our side has not changed our view on this," said Sen. Roy Blunt, a Missouri Republican. "I think where House Democrats failed (Tuesday), and maybe Senate Democrats failed, (and were) trying to use the time in a way that would wear us out ... and deny the President's team any response this week."
Sen. John Thune of South Dakota, the Senate's No. 2 Republican, told CNN that the record "is pretty complete" when asked if there should be witnesses.
Thune said that House Judiciary Chairman Jerry Nadler, a New York Democrat, was "especially partisan" last night and that is "not helpful to their cause frankly, because, you know, a lot of our members believe it was a partisan process coming out of the House and I think the tone (Tuesday) in many respects reinforce that. So if they're trying to win the argument that's probably not the best way to go about it."
Democrats say they forced the votes on witnesses and documents because the rules may not give them a chance to do so later in the trial. McConnell's rules have only teed up a general vote on whether additional witnesses and documents should be subpoenaed, which will end the conversation on witnesses if it fails.
"It was non-negotiable for us that the Senate at least consider the question of evidence witnesses and documents and the rules of a fair trial," Schumer said. "We would not be doing our job if we didn't try to make this trial fair. We're going to continue to do it."
House impeachment managers will have the next three days to make their case to senators, after McConnell backed away from a proposal for just two days amid complaints from key Republicans in his conference. After the House's time is done, the President's legal team will also get three days to give the President's defense. When opening arguments are complete, senators will get 16 hours to ask questions by submitting them through the chief justice.
At that point, senators will address the question of whether to have witnesses and documents — a vote that could signal the beginning of the end of the trial. Democrats need to peel off four Republican senators to back additional witnesses and documents.
GOP Sen. Susan Collins of Maine is one potential vote. While McConnell held the Republican conference together to oppose the amendments on subpoenas for witnesses like acting chief of staff Mick Mulvaney and former national security adviser John Bolton, Collins did join the Democrats to support one amendment, which would have given the two sides 24 hours to respond to trial motions on Wednesday. It was moot anyway — neither side submitted any motions.
Collins and other possible Republican crossovers say they want to wait until after the opening arguments before making a decision on witnesses.