Rather than walking up to the edge of a precipice that you can’t walk back from (I have little doubt that a liberal court-packing scheme would lead to a new raft of moves by the states and other organizations that would lead liberals to wish they’d never touched the Court) I’d suggest a less controversial move.
The reason that SCOTUS appointees are so politically hypercharged is twofold. The cowardice of Congress is the first; but let’s not digress down that path right now.
The second is simply math. Each seat on the SCOTUS holds 1/9 of the total power of the SCOTUS. We’d be better served, at this stage, by a larger court. Let’s pick 15 for the sake of argument.
On a one time basis, both parties pick three sitting judges (in that they’ve already gone through confirmation hearings) to move up to the SCOTUS. The ideological balance of the Court doesn’t move; but suddenly, each seat is less important; it’s 1/15 of the total power, not 1/9. Appointments become more common; appointment debates become less controversial and less heated, relatively speaking.
Another move, although more difficult to implement, would be to change the Court’s appointments from lifetime to 10-year terms. Again, the “heat” comes off the importance of the nomination. We’ve heard over and over again in the hearing “This is for a LIFETIME seat!”.
Well, if that’s what’s bothering you, change that little fact. :-)