After establishing rules for the impeachment trial Wednesday morning, the Senate is preparing to hear opening arguments at 1 p.m. from the House’s impeachment managers.

The impeachment managers and White House lawyers spent 13 hours debating 11 amendments to the rules resolution proposed by Senate Majority Leader Mitch McConnell (R-Kentucky).

All the amendments, including Senate Minority Leader Chuck Schumer‘s (D-New York) proposal to guarantee the inclusion of additional evidence and witness testimony, were voted down by the GOP majority. Only one vote did not fall along party lines.

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Just before 2 a.m., McConnell’s resolution was approved by Republican senators 53-47.

The resolution does not rule out the possibility of including witnesses or testimony, but requires the House impeachment managers and White House defense team to present their opening arguments first.

The House managers will have 24 hours over three days to present their arguments of how the president abused his power and obstructed Congress, and the White House defense team will have the same amount of time to make their case for dropping the charges.

Senators will then have 16 hours to question both sides before they decide whether to call witnesses or subpoena documents.

After a few GOP senators, including Susan Collins (R-Maine) and Rob Portman (R-Ohio) objected to McConnell’s original plan of condensing opening arguments for both sides into a two-day timeframe, he agreed to extend the beginning period of the trial an extra day.

The organizing resolution was also revised so that the House’s evidence can be used in the Senate trial, although the White House defense is still able to challenge what can be considered by senators.

The debate between the House managers and White House counsel became increasingly bitter after Rep. Jerrod Nadler (D-New York) insinuated that Republican senators were supporting a “cover-up,” prompting an intervention by the Supreme Court Justice presiding over the trial, Chief Justice John Roberts.

“I think it’s appropriate at this point for me to admonish both the House managers and the president’s counsel in equal terms to remember that they are addressing the world’s greatest deliberative body,” Roberts said. “One reason it has earned that title is because its members avoid speaking in a manner and using language that is not conducive to civil discourse … I do think those addressing the Senate should remember where they are.”

Schumer called the partisan resolution a “national grace.”

“On something as important as impeachment, the McConnell resolution is nothing short of a national disgrace,” Schumer said. “This will go down, this resolution, as one of the darker moments in the Senate history. Perhaps even one of the darkest.”