I've rather resisted the idea, but… Perhaps it is time to expand the court.
Just spitballing here: Maybe we should make it 21 or 25 justices as a permanent arrangement. For that first increase, each party should be permitted to put forward equal nominees approved by their party, with the current administration being given the odd last nominee. That should make it impossible for any one political wing of our government to ever pack the court.
We should also institute term limits because no position in a democracy should be a lifetime appointment. And, there must be minimum standards of experience which includes minimum time arguing cases and time on a lower federal court bench.