Video: Trump Impeachment Trial Day 1

Published Tuesday 7:24 a.m. | Updated Wednesday 12:04 a.m.

The Senate approved rules for President Donald Trump's impeachment trial in a party-line vote early Wednesday morning.

It marked the end of a very long first day that stood in contrast to how senators usually like to float above messy politics in what's known by some as the dignified "upper chamber," home of Congress' cooler heads and lofty rhetoric.

But as the courtroom of Trump's impeachment, the Senate seemed more like the economy cabin of an oversold flight on an especially tense, mandatory work trip.

The session went late into the night as senators considered fine-tuning the rules for the trial on two articles of impeachment.

The Democrats failed to win over any Republicans on their arguments for issuing subpoenas for documents. Republicans have defeated a series of other Democratic motions on identical party-line votes.

A Democratic victory came earlier in the day when the Senate’s majority leader, Republican Mitch McConnell, dropped plans for two late-night sessions to hear opening arguments, instead agreeing to spreading them over three days.

By the end, some senators were struggling to pay attention. That's in part because they've heard the story before about Trump's pressure on Ukraine to help him politically. And they're banned from doing almost anything besides taking notes and listening. No phones. No coffee. No note-passing.

So on Tuesday and early Wednesday, as the proceedings wore on, some senators rubbed their eyes. Sen. Bernie Sanders yawned. A few either nodded off or listened with their eyes closed. Keeping them focused will be a key challenge for the White House defense team and the House prosecutors. 

The trial's first several days are expected to be tangled in procedural motions on the Senate floor.

There's partisan disagreement on whether the president's conduct amounts to an impeachable offense and whether the allegations are sufficient to prove Trump is guilty. Democrats say Trump abused his power by urging the Ukrainian president to announce an investigation into political rival Joe Biden while withholding military aid to the country.

Trump's lawyers accuse the Democrats of a brazen attempt to overturn the results of the 2016 election and contend there's no evidence beyond hearsay that the president conditioned the release of aid on Ukraine agreeing to an investigation.