My head hurts!
What I've come down to is I would actually trade a decision finding Texas has no standing if the Court would expressly overrule Massachussetts v. EPA, which is what Texas is relying upon to have standing in the case. Massachussetts v. EPA is one of the worst cases of judicial activism of all time, and one that gives a lot of credit to Eternal Vigilance's argument about judicial oligarchy.
But hopefully the left will find out that the decision in Massachussetts v. EPA can work both ways. And from reading the briefs and commentary on the case, the left is absolutely horrified that their monster is being turned against them.