WASHINGTON - President Donald Trump's impeachment trial resumes for final arguments Monday before an expected acquittal later in the week that Democrats have said will be invalid because no witnesses testified.
The president was impeached in December for abuse of power over pressure on US ally Ukraine to announce investigations that would have helped him politically, including into Joe Biden, a leading challenger for this year's presidential ballot.
Biden is among the candidates Monday in the Iowa caucuses that choose the state's Democratic nominee and mark the official start of election season.
The selection process in largely rural Iowa, coinciding with final impeachment arguments in Washington, will be closely watched as a sign as to which of 11 Democratic candidates are gaining early momentum to challenge Trump in November's election.
At only the third impeachment trial of a US president, Trump is all but assured of being acquitted Wednesday, the day after his annual "State of the Union" speech, which the president said will carry a "very, very positive message."
Republicans hold 53 seats in the Senate to 47 for the Democrats, but a two-thirds majority, or 67 senators, is needed to remove him from office.
Adam Schiff, the leader of the House prosecutors, known as impeachment managers, told CBS on Sunday that it was "pretty remarkable" that senators on both sides had acknowledged that Democrats proved their case against the president.
"But I'm not letting the senators off the hook. We're still going to go into the Senate this week and make the case why this president needs to be removed. It will be up to the senators to make that final judgment, and the senators will be held accountable for it."
Republican Senators Lamar Alexander and Joni Ernst on Sunday said Trump's behavior was troubling but not impeachable.
Trump, though, on Sunday complained again, in a Fox News interview that he has been treated unfairly "from the day I won." (AFP)