HOW IT STARTS

On Jan. 15, Speaker Nancy Pelosi named her team of “impeachment managers,” the band of lawmakers who will argue their case on the Senate floor. In 1999, the House appointed 13 managers, each responsible for a nuanced aspect of the factual and constitutional case against Clinton. But Pelosi opted for a slimmer team of seven lawmakers, led by Intelligence Committee Chairman Adam Schiff, who led the impeachment investigation. The others include Judiciary Committee Chairman Jerry Nadler and Reps. Zoe Lofgren, Val Demings, Hakeem Jeffries, Sylvia Garcia and Jason Crow.

Senate rules require the chamber to receive the managers within a day after they’re named, and in this case, the trial formally began on Jan. 16.

Chief Justice John Roberts. | Jim Watson/AFP/Getty Images

The oath (day 1): On Jan. 16, the House managers arrived at the Senate, and Schiff read aloud the text of the articles of impeachment. The same day, Chief Justice John Roberts was ushered into the chamber by a committee of four senators to preside over the trial. (Fun fact: Of the six senators who escorted Roberts’ predecessor William Rehnquist into the chamber, just one remains in the Senate: Patrick Leahy of Vermont, and he was named to the committee a second time, the only senator in history to do so.)

Roberts, whose job will be to enforce the rules of the Senate as well as the procedures that the chamber ultimately adopts, will be sworn in and then administer an oath to all 100 senators requiring them to "do impartial justice according to the Constitution and laws.”

In 1999, senators didn’t swear just once. After taking the oath collectively, they were called on to swear individually by the chief justice and then sign an “oath book.” Senators even suspended the chamber’s rules to allow a photograph to be taken of the members being sworn in.

Trial briefs: The House and White House spent all of Martin Luther King Jr. Day weekend trading official briefs laying out their arguments — it was a far more expedited process than during the Clinton trial, which recessed for six days after the adoption of trial procedures. This time, the briefs were in hand before trial procedures were even considered.

The rules: On Jan. 20, McConnell introduced a set of rules to govern the trial, including the length of arguments and when motions to hear from witnesses would be allowed. If there are any last-ditch efforts to end the trial before it begins, it'll be hashed out at this stage. McConnell has already signaled he plans to approve a rules package with only Republican votes over the objections of Minority Leader Chuck Schumer and Senate Democrats. Under the rules of the Clinton trial, the Senate met every day except Sunday.



THE HEART OF THE TRIAL

Arguments (4 days): Here’s an area where McConnell has chosen to squeeze House Democrats. Just as in 1999, McConnell has proposed granting each side 24 hours of floor time to make their arguments. But this time, he's requiring that it be completed within two calendar days, ensuring that the arguments last deep into the night, if not the early hours of the morning. Though during the Clinton trial, neither side approached their time limit — even with 13 presenters on the House side — it's likely that this will test the endurance of senators and the House's trial team, who will be on hand for the entirety of the long days. White House Counsel Pat Cipollone is leading Trump’s defense along with Trump's personal attorney Jay Sekulow. They'll be getting assists from Clinton special prosecutor Ken Starr and retired Harvard constitutional law professor Alan Dershowitz, who were added shortly before the start of the trial.

This phase of the trial is likely when House Democrats will have their best, and perhaps only, chance to make an uninterrupted case to Americans that Trump should be removed from office for seeking Ukraine’s intervention in the 2020 presidential race. Though Clinton’s trial extended well beyond opening statements, there’s a significant likelihood that Republican senators will seek ways to limit Democrats’ chances to present evidence for the remainder of the trial.

Questioning (2-3 days): Senators are not allowed to speak during the proceedings. But after each team presents its case, senators have an opportunity to question the lawyers by submitting their questions to the chief justice of the Supreme Court. Just as in 1999, senators will have 16 hours of floor time to ask questions, a process that took three full days during the Clinton proceedings. Republicans and Democrats alternated posing questions under a handshake agreement to attempt to keep the time equal. Groups of senators submitted their questions to Rehnquist, who posed them to the House or White House lawyers. Here, too, is an area where McConnell may have leeway to deviate from the Clinton procedures.