This reasoned decision by the 10th Circuit makes clear that states cannot punish or in any meaningful way constrain an elector from voting his or her conscience.
Prospectively, this means that states must strike from their codes any statutory or regulatory infringement on the authority of an elector to think and not just act when it comes to choosing the president.
In implementing this reform, states might as well go ahead and also vote on the National Popular Vote Interstate Compact. Under that law, states would appoint electors nominated by the party whose candidate won the national popular vote. The electors cannot be punished if they choose otherwise, but the states plainly have plenary authority to appoint electors from the national vote winner‘s slate.
If states don’t want to pass the Compact then they still have to implement a method of appointing electors that preserves the freedom of these individuals to choose as president the person they think best suited for the job.
As I understand this case, they can choose any otherwise eligible American citizen.
Adopting the Compact might seem to many states the better way to organize the presidential selection system in the wake of this decision.