[flopriore]

I believe you're right, even if all the states agreed to make a similar change, this "equilibrium" state would be unstable. It would require an amendment to the US constitution to make it stable and that would require a huge majority.

Even if they decided to ament the constitution, you would still face another issue: now electoral system is written in the constitution, so it becomes even more difficult to change in the future.

What do you think about the system adopted by Maine and Nebraska instead?