California must push forward in a court-mandated project to reduce their overcrowded prison population to 137.5 percent capacity by the end of the year, according to a Friday ruling by the Supreme Court

The ruling, issued over the court's summer recess by Justice Anthony Kennedy (who handles recess matters for California), means that the state will have to obey a May court order to release 9,600 more prisoners by the end of the year. Kennedy's denial of a state request for a hold on the release order while it's appealed was issued without comment. But Justice Scalia had a lot to say about it in a strongly-worded dissent. Calling the order a "terrible injunction," Scalia agreed with the state's argument that additional prisoner releases at this point could be dangerous: 

"California must now release upon the public nearly 10,000 inmates convicted of serious crimes — about 1,000 for every city larger than Santa Ana— three-quarters of whom are moderate (57 percent) or high (74 percent) recidivism risks"

As SCOTUSBlog explains, Scalia also attacked the current ruling by referring to an earlier hint in an earlier Supreme Court decision that the state might be able to get a reprieve from the order:

"It appears to have become a standard ploy, when this Court vastly expands the Power of the Black Robe, to hint at limitations that make it seem not so bad...Comes the moment of truth, the hinted-at limitation proves a sham." 

Scalia was one of three dissenting justices, along with Samuel Alito and Clarence Thomas. The state, largely backed up here by Scalia, argued that the conditions in their prisons have improved dramatically since earlier orders set the release numbers. Plus, they say, fewer than 1,800 prisoners left in their system are low risk. 

A series of lawsuits going back decades alleges that the overcrowded conditions in the prisons are mental and physical health threats to inmates, in violation of the Constitution. The Supreme Court agreed in 2011, saying that the conditions amounted to cruel and unusual punishment. As federal judges threaten to hold Gov. Jerry Brown in contempt if he doesn't meet the end-of-year capacity requirements, the system has faced a number of high-profile problems recently. There's, for example, the inmate hunger strike against solitary confinement conditions, now in its fourth week. Meanwhile, medical care for the entire California prison system is under receivership after a judge's ruling that its conditions amounted to cruel and unusual punishment.