The trial began after the House of Representatives delivered to the Senate two articles of impeachment on which a majority in the House had voted to send to the Senate. The Senate voted to give each side a total of 24 hours over three days each to present their case. The impeachment managers used every bit of their time to present their case; the President's defense team used 14 hours to present their case.

The next phase involved questions from individual Senators to the Senate as a whole, to be answered by either the impeachment managers or the President's defense team. Following the rules set down by the Senate during the first presidential impeachment trial–of Andrew Johnson in 1868–the Senators handed their questions to the presiding officer, Chief Justice John Roberts, who read the questions publicly.

Once all of the questions had been asked and answered, the Senate took up the issue of whether they would call additional witnesses. During the question-and-answer session, new revelations that would seem to have a bearing on the case had emerged. And in the two previous impeachment trials, of President Johnson and of President Clinton, the Senate trial had incorporated witnesses. (Indeed, in Clinton's trial, the President himself testified.) This time, however, the Senate voted to not call any additional witnesses.