There are only two options, Senators.

 
Donald John Trump invited and encouraged an armed assault on the Capitol of the United States for the purpose of preventing Congress from carrying out its constitutionally-mandated obligation to count and certify the votes of the Electoral College because he lost.

This was an attempted coup. 

The overwhelming majority of constitutional scholars believe that it is perfectly proper to impeach a former president since disqualification from serving in the future is one of the options available on conviction as well as removal from office. The Fourteenth Amendment even requires the disqualification of a person who has engaged in an insurrection against the United States. Not only that, but it was only because Republican Senate leader Mitch O'Connell refused to permit it that the trial did not take place while Trump was still president. The evidence is undeniable and there is no excuse for the Senate not to act.

If Donald Trump does not warrant impeachment and trial and disqualified from ever again holding Federal office, nobody ever has and nobody ever will. If Trump is not convicted, impeachment will effectively be a dead letter.

The members of the Senate are not merely the jurors in this case. They also are witnesses and victims. And if Trump is acquitted, they will also be accomplices.