How long will and should the Senate impeachment trial last?

I’m somewhat baffled by what appears to be the current Democratic game plan, which is to not call any witnesses at Trump’s second impeachment trial. If this is indeed the plan and remains so, the whole thing will be over in about a week from today.

I don’t get it. Under the rules it has adopted for this proceeding, the Senate can still conduct other business, so that’s not it. I understand every halfway decent human being is sick to death of Donald Trump and would love to never speak of him again, but Trump is being judged for a series of acts over two months’ time that collectively are probably the worst and most destructive thing any American president has ever done to the integrity of our entire political system. That seems like the kind of event you would like to evaluate in some detail before pronouncing judgment.

That’s all as a matter of principle. On a pragmatic level, how does it not make sense to drag the GOP on this in a nationally televised proceeding for weeks if not months?

Again, this just doesn’t make sense to me.