There’s an interesting article in Bloomberg from a Harvard law professor on the same-sex marriage case in Puerto Rico. This one provides some analysis from an actual legal expert on the usage of the Insular Cases in the decision. The author thinks that the reasoning in the decision is ultimately not well supported but also that the status of Puerto Rico as defined by the Insular Cases is basically indefensible.
A federal judge has invalidated same-sex marriage in Puerto Rico. The general consensus seems to be that this will almost certainly be overturned at the Supreme Court, which ruled that same-sex marriage is a constitutional right. One interesting thing that people have brought up is that the judge cited the Insular Cases, which were a series of court cases from the early 1900s defining the relationship between the US and its newly acquired colonies such as Puerto Rico, Guam, and the Philippines. Among other things, they basically created a form of second-class citizenship for the residents of those places and declared that most constitutional rights didn’t need to apply in colonies. Most of that has since been overturned by Congress but as far as I know the Insular Cases largely still stand as a matter of constitutional law. It would be interesting, then, if the modern Supreme Court ends up returning to those decisions.