I believe her clerks are “voting” absentee on her behalf
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That should be verified, and once verified the vote should be redone. No one has the authority to vote for anyone else in our Republic. If RBG is unable to vote, by showing up, her vote should not be counted.
A Senator can’t dial in his or her vote, nor can a House Member.
No one has authority over how the Supreme Court conducts its business. If Congress doesn’t like it, they can impeach, or reduce or expand the number of justices.