The US Senate gathered on Tuesday afternoon and began the impeachment trial of President Donald Trump. Before the trial began, House impeachment managers sent a letter to the White House expressing concern over Pat Cipollone serving as an advocate-witness for Trump.

After the letter was sent, House Intelligence Committee Chairman Adam Schiff (D-CA) held a press conference where he condemned the resolution Senate Majority Leader Mitch McConnell (R-KY) proposed late Monday night. The resolution laid out the procedures for the trial, which limited the House’s ability to present to 24 hours over the course of two days. The House managers promptly released a statement that claimed the procedure “deviated sharply from the Clinton precedent” they were promised.

After Chief Justice John Roberts arrived to preside over the trial, the Senate debated over the revised trial rules, which extended the House’s presentation days from two to three.

After opening remarks and arguments from both sides, the Senate voted on three different amendments by the House proposing subpoenas for documents tied to Ukraine. Each was struck down along party lines.

The president is currently in Switzerland and missed the first day of the trial, but weighed in through a tweet.

The impeachment trial will resume again on Wednesday.