Last Sunday, I asked the rhetorical question, What will John Roberts do?
Turns out, he'll do exactly as expected. He's punting, but probably on Constitutional grounds. The Constitution requires the Chief Justice to sit on an impeachment of the President, but Donald Trump is no longer the president, so it falls to the the President pro-tempore of the Senate to preside over the trial.
So, if Leahy is presiding, he can't vote, and if Commie Harris ain't there, the Democrats don't have a majority. Isn't it amusing what a 50-50 Senate can do?