As the Senate impeachment trial of President Donald Trump got underway Tuesday, the two parties retreated into their respective corners.
 

Republicans said their ground rules for the trial were fair and even-handed; Democratic Minority Leader Charles Schumer of New York begged to differ.

"Leader McConnell wants a trial with no existing evidence and no new evidence," Schumer said on the Senate floor. "A trial without evidence is not a trial; it's a cover-up."

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But Senate Majority Leader Mitch McConnell did give some ground Tuesday: House Democrats, who have 24 hours to lay out their opening argument, can now spread that time over three days, rather than two. And the records from the House impeachment will now be automatically entered as evidence in the Senate trial, another last-minute change.

But the central question is whether to allow new evidence and new witnesses, potentially including former national security advisor John Bolton.

Members of Trump's legal team rejected the idea, arguing House Democrats had failed to build a case.

"It's ridiculous," said White House Counsel Pat Cipollone, the president's lead lawyer. "Talk about the framers' worst nightmare. It's a partisan impeachment that they delivered to your doorstep. In an election year. Some of you are upset because you should be in Iowa right now. But instead we're here. And they're not ready to go. And it's outrageous."

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As day stretched into night, Schumer introduced a series of subpoena requests. Each was voted down along party lines, 53-47, but the debate allowed House impeachment managers to begin building their case against Trump, who attempted to thwart their investigation at every turn.
 

"President Trump's complete and total obstruction makes Richard Nixon look like a choir boy," said New York Rep. Hakeem Jeffries, one of the House managers prosecuting the case.
 

Opening arguments in the trial begin Wednesday and will likely stretch into next week. Then comes the critical vote on allowing witnesses and documents.

"Let's get this trial started, shall we? We are ready to present our case. We are ready to call our witnesses," House Intelligence Committee Chairman Adam Schiff, one of the House managers, said on the floor of the Senate on Tuesday. "The question is, will you let us?"