This is interesting. It describes the rules, such as they are, that will govern the impeachment trial in the Senate. The proceedings will be presided over by Chief Justice Roberts but that’s separate from the role of the judge which falls collectively to the Senators…they are judge and jury. The author compares the rules governing impeachment to Calvinball…the rules are pretty much whatever 51 Senators want them to be.
The rules under which Donald Trump will face trial in the Senate are a combination of theatrically detailed and maddeningly vague.
— Read on www.lawfareblog.com/imagining-senate-trial-reading-senate-rules-impeachment-litigation