TBH, this position is really absolutely irrelevant. SCOTUS blog (above) clearly states that the position is just as an observer of proceedings and serves no other means. Doesn't even have to be a judge, just someone in Senate. I am guessing, and again only IF Roberts recuses himself, that Chucky and McConnell will move to appoint someone. I am also guessing that none of the SCOTUS conservative judges will be considered. Doesn't really matter in the end. I cannot imagine that someone like Thomas or Alito would even want to preside at an ILLEGAL impeachment trial while having absolutely no way to interfere and set things straight. Watching 50+ utter idiots play out illegal circus would be a maddening experience for any real attorney, and judge. Torture, really. Rand Paul already stated this is what Roberts told him as his reason to recuse himself. Questionable, sure, but I'll go with Rand's statement for now.

In the end, the ONLY decision that matters is the final vote after the trial. 67 Yays. VP cannot vote. Senators only.

Traditionally, it was chief justice. So, Roberts or not, it really doesn't matter in the end. Chucky and McConnell will set some more rules, I am sure, but in general, Senate impeachment rules are already mostly spelled out (~20 pages worth). I know that many keep on thinking that Trump will be allowed to present election fraud facts, but the reality is that Senate sets the rules for what can be presented, or not, and the only charge the House voted on is "incitement for riot". Doesn't matter what Trump said at the rally, they will only concentrate on what they want, incitement. You know, his call to come to D.C. for a rally on Jan. 6. And nothing else.

Reality. Sad one. Sometimes what we want and expect, and wish for, by law, is not what we actually get. As long as GOPe holds steady, Chucky and McConnell won't be able to convict.