The second impeachment of Donald Trump, the 45th president of the United States, occurred on January 13, 2021, one week before his term expired. It was the fourth impeachment of an United States president, and the second for Trump after his first impeachment in December 2019. Ten Republican representatives voted for the second impeachment, the most pro-impeachment votes ever from a president's party. This was also the first presidential impeachment in which all majority caucus members voted unanimously for impeachment. The House of Representatives of the 117th U.S. Congress adopted one article of impeachment against Trump of "incitement of insurrection", alleging that Trump incited the January 6 storming of the U.S. Capitol. These events were preceded by numerous unsuccessful attempts by Trump to overturn the 2020 presidential election, as well as his pushing of voter fraud conspiracy theories on his social media channels before, during, and after the election. A single article of impeachment charging Trump with "incitement of insurrection" against the U.S. government and "lawless action at the Capitol" was introduced to the House of Representatives on January 11, 2021. The article was introduced with more than 200 co-sponsors. The same day, House Speaker Nancy Pelosi gave Vice President Mike Pence an ultimatum to invoke Section 4 of the 25th Amendment to assume the role of Acting President within 24 hours, or the House would proceed with impeachment proceedings. Pence stated that he would not do so in a letter to Pelosi the following day, arguing that to do so would not "be in the best interest of our Nation or consistent with our Constitution". Nevertheless, a House majority, including one Republican, passed a resolution urging Pence to invoke the 25th Amendment.The House impeachment managers formally triggered the start of the impeachment trial on January 25 by delivering to the Senate the charge against Trump. The nine managers walked into the Senate chamber led by the lead impeachment manager, Rep. Jamie Raskin, who read the article of impeachment. The trial in the Senate was scheduled to start on February 9. Chief Justice John Roberts chose not to preside as he had done for Trump's first impeachment trial; the president pro tempore of the Senate, Vermont Senator Patrick Leahy, presided instead. At the trial, the first of its kind for a departed U.S. president (with Andrew Johnson, Bill Clinton, and Trump having all been the incumbent in prior impeachment trials), 67 votes or a two thirds majority was needed to convict Trump. Ultimately, 57 senators voted "guilty" and 43 senators voted "not guilty", resulting in Trump being acquitted of the charge on February 13, 2021.