At the risk of departing from the Twitter consensus, I don't think it makes much difference whether witnesses are called or not in this trial.

And I'm not just talking about the final vote on acquittal vs. conviction. Arguments that public opinion will be swayed by a few depositions, or we'll learn some major fact we wouldn't have learned otherwise, seem to me based more on emotion/partisanship than cold analysis.

We're now entering Year 7 of "once people find out [X] about Trump, they'll change their minds about him!" This has rarely been true, and I suspect that few of the actually plausible cases of [X] at this point relate to the procedural behavior of the Senate.