I had posted earlier on the opinion of the First Circuit Court of Appeals that it is unconstitutional to deny Supplemental Security Income (SSI) benefits to an American citizens living in Puerto Rico even though that same person is eligible if living in one of the 50 states (or the Northern Marianas). We'll see what Social Security does about that ruling. My guess is that they think about it and then file a petition asking the Court to rehear the case en banc, that is by all members of the First Circuit Court of Appeals rather than by a three judge panel, as is normally the case.
It's worth noting that Puerto Rico isn't the only U.S. territory with this sort of litigation. There's also a case pending in the U.S. District Court for Guam and there should be a decision in that one soon. The case in Guam presents the issue more directly than the Puerto Rico case since it concerns a claim for benefits as opposed to an overpayment allegedly created when a person who was getting SSI moved from New York to Puerto Rico.
The Guam case may not matter since it isn't as far along as the Puerto Rico case and since Guam is so much smaller than Puerto Rico but that case also holds out the prospect of the Supreme Court refusing to hear the Puerto Rico case because there has been no disagreement between Courts of Appeals on the issue of SSI in territories. Disagreement between Courts of Appeals is the most important reason why the Supreme Court agrees to hear cases. I'm not sure exactly where it leaves Social Security if the Supreme Court refuses to hear the Puerto Rico case since it doesn't directly involve a claim for benefits.
By the way, I've been surprised that Social Security didn't raise the defense of res judicata in the Puerto Rico case. Presumably, Social Security first declared the overpayment administratively before suing to get a judgment on the overpayment. If the agency did, it looks as if the claimant didn't appeal. Arguably, the claimant should have raised any defense to the overpayment at that time rather than later when he was sued. If the government sued first without giving the claimant an opportunity to fight the overpayment administratively, I think he was denied all the process he was due. Perhaps both parties were eager to get to the constitutional issue.