It is a question that merits its own Federalist Paper: When the legislature consistently fails in a fundamental duty, should the courts step in to provide a remedy?

That the state of California has failed to run a humane prison system is beyond dispute. About 143,000 prisoners are packed into a system designed to hold 80,000. Overcrowding results in unrest, poor sanitation and untreated illness. It is also beyond dispute that California's legislature, despite more than a decade of prodding by the courts, has not adequately addressed these problems.

Prison overcrowding exposes a democratic disability: Some states are unwilling to provide reasonable services to a group toward which the public is profoundly unsympathetic. So in 1996, Congress passed the Prison Litigation Reform Act, giving federal courts oversight over dysfunctional state systems. The law allows for caps on prison populations if there is no reasonable alternative.

This combination - an incorrigibly irresponsible state legislature and a federal legislative mandate - was an engraved invitation to judicial activism. A panel of three federal judges in 2009 ordered the California prison system to reduce its population to 137.5 percent of capacity. Absent other reforms, this would eventually require the release of 37,000 prisoners. A divided Supreme Court upheld the panel's ruling. Justice Anthony Kennedy - a Californian with a long-term concern about prison conditions - wrote the decision.

Court conservatives raised a number of practical concerns. Was this really the least intrusive method to achieve the goal? Should more recent progress in California have made its way into the court's calculation?

The weightiest argument, however, came from Justice Antonin Scalia. He objects to judges adopting the role of politicians. "Structural injunctions," such as the one issued by the federal panel, turn "judges into long-term administrators of complex social institutions such as schools, prisons and police departments." Courts are pushed beyond their competence, making choices naturally informed by political bias. The abdication of public officials, in Scalia's view, does not automatically transfer their role to the judiciary. Incompetence alone is not an excuse for intervention. If a state's foster care system is ill-designed - or a city's public school system is persistently dysfunctional - should judges be able to impose specific reforms?

The proper legal response seems to be: It depends. In his dissent, Justice Samuel Alito says "undesirable prison conditions that do not violate the Constitution are beyond the federal courts' reach." Which implies that unconstitutional conditions would be within the federal courts' purview. This is the central dispute in the California case. Justice Kennedy believes that extreme overcrowding leads to inevitable violations of the Eighth Amendment forbidding cruel and unusual punishment. Conservatives on the court believe conditions in California prisons are "undesirable" but not unconstitutional.

This disagreement should not, however, distract attention from the true offenders in this case. California politicians have been complicit in the erosion of their own authority. They have approved mandatory minimum sentences and "three-strikes" measures - without building enough cells, hiring enough staff or holding low-risk offenders accountable in more creative ways than incarceration.

The result was predictable. As Kennedy reported in his ruling: "Because of a shortage of treatment beds, suicidal inmates may be held for prolonged periods in telephone-booth sized cages without toilets. A psychiatric expert reported observing an inmate who had been held in such a cage for nearly 24 hours, standing in a pool of his own urine, unresponsive and nearly catatonic. Prison officials explained they had 'no place to put him.'"

At the end of his dissent, Alito warns that a large prisoner release in California might lead to a "grim roster of victims." Of course, nearly all prisoners are eventually released after serving their time. We are only debating the pace. And it is absurd and outrageous to treat them like animals while hoping they return to us as responsible citizens.