I don’t think he can, but he shouldn’t give up the fight before it’s even started. If you have the presidency the bully pulpit you could at least start to put the idea into the minds of the Americans and normalize. It certainly better than just bending over.
Mean there’s not a very good chance for a single-payer healthcare system to be instituted anytime soon but that doesn’t mean politician shouldn’t openly advocate for it.
We should probably just abolish the court as it has no functional value anyways.
The fact is, Republicans effectively stole to supreme Court seats based on legislative tactics. This is basically unprecedented.