It’s Powell’s clients who need to have standing, not Powell herself.
However, because this case is on appeal, SCOTUS has the discretion to not hear the case, and they don’t even need to give a reason. They can simply deny certiorari.
That was what was different about the Texas case. Suits between states are tried at SCOTUS under the Court’s exclusive jurisdiction - there isn’t any other place.
Thank you very much for your detailed response. I greatly appreciate it.