That question is why I cannot see the SC going with the Vattel definition no matter how convincing the evidence for it. Of course, that assumes it ever gets to them and I’m sure they will be content with district and/or appellate courts finding a lack of standing.
Really. We’re talking about the same institution (different players) who found a constitutional right to privacy and right to abortion. Should they want to ignore Vattel, would they let themselves be deterred?