The opening day of the second U-S Senate impeachment trial of now-former President Donald Trump will likely be a debate on whether the proceeding itself is constitutional. Carleton College analyst Steven Schier says:

“Clearly constitutional for the House to pass the articles of impeachment, but we’ve never had a former president held up for an impeachment trial. So this is unprecedented territory.”

And Schier says beyond that, there is not strong evidence that the former president committed “high crimes and misdemeanors” necessary for a conviction in the U-S Senate:

“What you need is strong, empirical proof of an organized attempt to attack the Capitol of the United States, in which the president was a party to the planning and the operation of that — and right now, we don’t have that.”