After two weeks of testimony and questions, members of the impeachment managers team and the President's defense team delivered closing arguments and then the Senators voted. A total of 67 Senators would have had to have voted to convict the President. On the first Article of Impeachment, alleging abuse of power, the Senate voted 52–48 against. On the second Article of Impeachment, alleging obstruction of Congress, the Senate voted 53–47. Republicans hold a 53–47 majority in the Senate. All Republicans voted to acquit the President on the second Article of Impeachment. All but one Republican voted to acquit the President on the first Article of Impeachment. The only Republican to vote to convict the President on the first Article of Impeachment was Mitt Romney of Utah. He became the first Senator in the history of the U.S. to vote to convict a President who was a member of the same political party. This did not occur in the previous two presidential impeachment trials, that of Andrew Johnson in 1866 and of Bill Clinton in 1998–1999.

The House Intelligence Committee had conducted hearings to investigate claims that Trump had put pressure on the government of Ukraine–specifically President Volodymyr Zelensky–to announce that it was investigating Joe Biden, a former Vice-president and then a potential (since formally running for President) presidential candidate. The details of the pressure involved allegations of withholding aid until the Ukrainian government made a public announcement that it was investigating Biden and, specifically, his son Hunter's dealings in Ukraine. That was not the only investigation that Trump wanted Ukraine to announce, according to the impeachment articles. The other investigation was to be into the conduct of Ukrainian officials during the 2016 U.S. presidential campaign and whether those Ukrainian officials interfered with the U.S. election, which was won by Trump.

The second article of impeachment charged that the White House refused to comply with House subpoenas for information and/or testimony in connection with the impeachment investigation and, further, that the White House directed other agencies in the Executive Branch to do the same.

On Dec. 18, 2019, the House as a whole voted 230–197 to charge Trump with abuse of power and 229–198 to charge the President with obstruction of Congress.

The House's impeachment managers and the President's defense team had 24 hours each, spread over three days, in which to lay out their case. Then, it was time for questions and answers. Chief Justice of the United States presided over the trial, and it was his job to read aloud the questions asked by individual Senators.