We expect conservative and liberal justices to vote differently, and not because of their adherence to particular outcomes.
In general, conservative justices see their role as that of an umpire, applying the rules in a reasonably mechanical fashion. It doesn’t matter if one batter has a really compelling life story, or one fielder’s success is what the game of baseball needs to really prosper. If the rules say the batter is out, he’s out. If the rules say the fielder made an error, he made an error.
In general, liberal justices are themselves as having a role and a responsibility to shape the law and the land – to be a part of the living Constitution. They want to make a difference, to leave the state of the law better than they found it, to help the country’s social policy grow and mature, to be a voice for the evolving standards of decency that are the mark of every civilization.
There is nothing objectively in error about either belief.
In my opinion, the proper role of judges (shocker!) is more correctly described by the first paragraph than by the second.
But it means that, in good faith, Justice Ginsburg and Justice Alito can reach different results on questions like the ACA. Justice Ginsburg can say, “Look, it’s the mark of a decent society to provide a basic level of health care to all its members, and the role of the federal government has expanded enough over the years that an individual mandate simply passes the common sense test of Congress’ powers.”
And Justice Alito can say, in equally good faith, “Look, the federal government’s powers have a limit, and this extends that limit. The way for our nation to extend the powers of the federal government is not by action of the courts; those are not the rules. The rules require an amendment, or absent that, they require fidelity to the words of the Constitution.”
Which Justice is objectively wrong?
Neither one. Both are hewing to their judicial philosophies.