The start of public impeachment hearings in the House this week are likely to push the race for the White House into a new phase, testing whether Democratic efforts to investigate President Donald Trump risk hurting the party in the 2020 election.
Democratic front-runner Joe Biden will also be a central figure in the proceedings, which will challenge his political resilience. And six senators in the running, including top contenders Elizabeth Warren and Bernie Sanders, will be jurors in a trial that may force them off the campaign trail at a crucial moment.
While U.S. public opinion has moved in favor of impeachment, the country is deeply divided along party lines and Trump remains highly competitive against top Democrats in swing states like Michigan, Florida and Pennsylvania that played the key role in his 2016 victory.