“Allowing the will of the voters of any state to be trumped by the national popular vote is a basic violation of our constitutional structure, and I think that even most liberals on the court will agree.”
There is no such thing as the will of the voters when it comes to choosing presidential electors.
That power was delegated to state legislatures under Art II, Sec 1.
There is a difference between choosing presidential electors and dictating how they must vote, or changing their votes based upon what happens in other states. I'm amazed that so many people on FR can't see that distinction.
By the way, presidential electors are chosen BEFORE an election, not afterwards. They are not chosen based upon the actual vote either in their own state or in the country as a whole. They are usually chosen by a formula based on the composition of the state legislature.