I wondered what authority he might have in this matter.
I’m not exactly sure but there is a clear law on the books saying judges MUST recuse if they were defending/involved in presenting a side of a case that eventually makes it to a court they are a judge or justice on. He could clearly require her to recuse on that basis. However they don’t because as “peers” they expect all of them to be self-regulating and know when to recuse themselves. Of course the liberals won’t.
If a republican appointed justice did what Kagan did we’d have lib politicians, and media pundits screaming they must recuse themselves or the ruling means nothing. Violence in the streets. Seriously. But lib justice Kagan doing this, not a peep out of the media or lib politicians.