Term limits and age limits make sense to me, but voluntary retirement, especially under pressure, does not. Just how impaired must a senator be for the "Feinstein Rule" to apply? Does it matter what party the senator's governor is from, or whether he wants the seat for himself?

DF's staff knows how to do her job. Let her fill the seat so long as she can show up to be counted. If she cannot do that, she should be removed, because not showing up creates a bright-line precedent. In short. being there matters; being all there, not so much.