Impeachment: Senate trial set to begin February 8. What happens next? A 2/3 majority vote is needed for a conviction, requiring 17 Republicans to join the Senate's 50 Democrats. Author: Emily Longnecker Updated: 3:03 AM EST January 27, 2021 WASHINGTON — One hundred US Senators raised their right hands and took oaths Tuesday afternoon, sworn in as jurors for a historic impeachment trial. “We tend to say this might be a once-in-a-lifetime event and for many of them, it is now becoming an annual event, something they never would have anticipated or something a year ago, they certainly would not have seen coming either,” said Ted Frantz, a history professor at University of Indianapolis.