The constitution doesn't say outright one way or the other, but the CJ did cast tie breaking votes in Johnson's trial. There is of course no tie on conviction - it takes 2/3 of the senators present. Common sense suggests that the constitution's use of the term "presides" include the tie breaking vote the VP has in presiding over other Senate business.
I actually agree with this. If the CJ's role was to be purely ministerial, without any independent exercise of judgment or authority, then why didn't the Constitution just let the Majority Leader run things? Why bring in the Chief Justice if he's
not supposed to exercise some independent judgement?
I'm not saying that I
want him to do that -- I hope he doesn't. I'm just saying that from a purely objective legal perspective, he probably should.
I suppose the argument on the flip side is that "the Senate" is supposed to decide the rules for impeachment, and Robert's Rules are part of the the Senate's standing rules. And under Robert's Rules, a tie vote fails. That particular rule would not be necessary if all ties had to be broken. Therefore, you could argue that ties should not be broken unless specifically stated elsewhere, and there isn't anything saying that the CJ should cast tiebreaking votes.
Maybe I've just argued myself into the opposite opinion....
Crap.
