Guess the only reasonable recourse at this point for the next Dem president is court packing.
I've heard some really good ideas on reforming the court, my favorite has been 13 federal circuits = 13 supremes, Supremes must come from each one of the federal circuits (so they have an established history of decisions behind them) and are cycled down to the circuit once their term is up (which is technically in compliance with the constitution as they are not being "removed") but that seems too complicated to actually pull off. Turns the whole thing into an actual job instead of whatever the fuck it is right now.
A more functional solution I've read is that each President gets 4 Supreme court picks no matter what. This would naturally cause the court to balloon in size for a few presidential cycles until the retirements equalize with the onboardings. This not only dilutes the power of each supreme, but also eliminates the whole "tactical retirement" element of Supremes negotiating their successor with a friendly Administration. This wouldn't even technically require any new laws, just a friendly Senate moving confirmation hearings along at a steady clip.