By Sherry Colb In my column for this week, I discuss the case of Plata v. Schwarzenegger , in which the Supreme Court is reviewing a three-judge federal district court's order that the California prisons reduce their overcrowding from 200% of capacity to 137.5% of capacity, within two years. If the Supreme Court affirms the order, then California will probably have to release approximately 40,000 prisoners (though it can, in theory, build more prisons or pay for prisoners to be transported to facilities outside the state prison system). The underlying constitutional violation, to which the overcrowding reduction measure is addressed, is a state of medical care that is so deficient that it violates the Eighth Amendment prohibition against cruel and unusual punishments. Because other approaches to the problem have failed, the California federal court concluded that the only way to remedy the problem is reduce the overcrowding substantially. In my column, I discuss the default