Brief, but an idea I would like to see more widely discussed:
If Democrats can’t stop the latest Supreme Court nomination, then they should do like the Republicans do when they regain power: don’t hesitate to change the rules. Make a new rule (actually a return to the traditional rule) that Supreme Court Justices must be confirmed by 60 votes, and any justices not confirmed in the past by 60 votes must submit to reconfirmation by the old rules. Or just declare that the Court now consists of eleven justices, and confirm two more, using whatever rules they want.
In other words, stop bringing carrot sticks to knife fights. You can’t win against cheaters if you docilely accept the cheaters’ ad hoc rules.