For much of Puerto Rico’s history, Congress treated it very much as if it were a dependent colony, giving it self-governing authority only little by little, but always retaining a veto power over what the territory’s government chose to do.   Even now, Puerto Ricans cannot be sure whether their 3.7 million people live in a territory, or something like a state, or something in between.  Officially, it is a commonwealth, but the constitutional consequence of that status remains somewhat uncertain.

There continues to be a good deal of agitation among some of its people to move out of Congress’s shadow, if not to gain equal status of statehood (a controversial proposition among Puerto Ricans), but as something more than a colony.  In fact, since the end of World War II the instinct for self-governance has grown.  That has paid off at least once, and the meaning of that incident is going to be spelled out within coming months by the Supreme Court.  On Thursday, the Justices agreed to hear an appeal by the Puerto Rican government, a fervent plea for the constitutional rank of sovereign entity – at least for some purposes.

The government’s leaders are persuaded (but their own Supreme Court majority is not) that Puerto Rico achieved that august status in 1952, when the people wrote their own constitution – albeit under a grant of authority given by Congress in 1950, in what is technically known as Public Law 600.   Once that grant became embodied in a homegrown constitution, Puerto Rico’s status may well have moved closer to sovereignty; but just how much closer?

In the history of governments, of course, true sovereignty means the capacity to govern one’s own affairs.  And when sovereignty is twinned with democratic principles, it means that government is by consent of the people.

Nations, of course, have a different kind of sovereignty in the international community.  But it still flows from the same concept of the capacity to manage their own affairs, without being supervised by some “higher” body, without their consent.

For America’s national government, of course, sovereignty in managing the nation’s affairs ultimately rests with the people – the one truly original idea of governing that the founders adopted as they shook off the notion that sovereignty resides in the king or queen.

But a political community below the national level can also be sovereign, at least to a degree.  Under the American Constitution, in fact, state governments do have a measure of sovereignty, the Supreme Court has said repeatedly.  They are the managers of their own affairs, within the realms of public policy that have been traditionally managed closer to the people – like public health and safety.  The power to pass criminal laws is a very important example of that kind of sovereign authority.

What Puerto Rico is now seeking in the Supreme Court is that level of sovereign choice – the ability, on its own, to enforce the criminal laws that it enacted as a commonwealth government, under Public Law 600.   The case the Justices will decide is focused specifically on whether Puerto Rico can prosecute someone for the very same crime that federal prosecutors have charged, without violating the Constitution’s protection (in the Fifth Amendment) against “double jeopardy.”

The Supreme Court has said that state governments may prosecute the same offense as federal prosecutors pursue because, for this purpose, the two are sovereign entities.  If they were one and the same, of course, the Fifth Amendment would prevent them from taking turns trying the same crime in their own courts.

That is the argument of “dual sovereignty” that Puerto Rico now want to share in, to run its criminal courts as it sees fit (within limits, of course, set by the national Constitution).  Its own Supreme Court, however, has barred that aspiration, concluding that such sovereignty as Puerto Rico has is merely the same as that possessed by the national government, and especially by Congress in Washington.  They thus cannot take turns prosecuting the same crime.

What that has done to Puerto Rico, its government complained to the Supreme Court, is that it “strips it of the ability to enforce its own criminal laws without federal interference,” and that has turned what Congress gave Puerto Rico in 1950 into “a monumental hoax.”   State governments elsewhere in the United States, it notes, share “dual sovereignty” with the federal government for purposes of criminal law enforcement.

The Puerto Rican government’s comment about a “hoax” is borrowed from a decision by the federal appeals court that hears federal cases coming up from Puerto Rico – the First Circuit Court of Appeals, which sits in Boston.  That court has ruled directly contrary to what the Puerto Rican court has now ruled – setting up the specific conflict that has now attracted the Supreme Court’s attention.