Nebraska v. Biden was something of a surprise. Based on my read of the briefs and oral argument, I came to the tentative conclusion that Missouri lacked standing. But the Chief Justices's opinion was more persuasive than I expected. Then again, the Chief can be extremely slippery with his legal analysis.
I have no idea if the Missouri Attorney General can sue on behalf of the Missouri Higher Education Loan Authority (MOHELA). The majority resolved this issue largely on the basis of Arkansas v. Texas, which allowed Arkansas to sue on behalf of the University of Arkansas. The dissent responded that the University of Arkansas lacked an independent basis to sue, while MOHELA does have such authority. Rather, the dissenters parsed through decisions of the Missouri Supreme Court which found that similar institutions were not instrumentalities of the state. Does the dissent accurately read Missouri law? Who knows?
It seems to me that the correct course here would have been for the Eighth Circuit to certify the question to the Missouri Supreme Court. That body could have authoritatively resolved the status of MOHELA. Given that the Supreme Court's ruling sweeps nationwide (hello nationwide vacatur!), certification would have been appropriate. Instead, we are left with a standing analysis that is probably good for one ride. Well, if the Biden Administration goes forward with another executive action on student loan relief, Missouri can once again say mahalo MOHELA.