But the argument that "it's OK for us to do it, because they would" seems a bit thin.
It's OK to loot this store because if I don't someone else will...
And it's OK to do anything I like as long as I can point a finger and say "but he'd do it too"
So, yeah, this is a textbook case of hipocrasy, but being hipocratic doesn't matter as long as we win.
The reality of the situation is that in the US one party constantly pushes boundaries and test limits. The other party then adjusts to attempt to counteract that. Yet it’s sold as “both sides are just as bad as each other”
Court expansion hasn't happened yet, but if it does:
1. Them's the rules; sauce for the goose, sauce for the gander. (Or: Live by the rules, die by the rules.) (Or: Karma's a bitch, ain't it?)
2. What you call the "structural features of our government and institutions" are meant to serve the people, not vice versa. It's idolatry to put those features on a pedestal and declare them to be immutable. Presuming adequate protection of genuine minority rights, it's not illegitimate for a democratically-elected government to use lawful means to try to restructure existing institutions in pursuit of the majority's felt political needs.
In this case, the left is marching forward with all sorts of new policies—often ostensibly to deal with a societal problem, but causing more problems because the policy does not derive from first principles.
He will do whatever it takes to hold on to his minority power. He did it with Obama and has already hinted ~2 hours after RBG died he'll happily do a 180 on his previous position this time around when he has the chance.