Noah Feldman at Harvard picks up on a trait of SCOTUS' swing Justice:

As it happens, some of Kennedy’s principles were on display in the California prisons case. The facts were simple: California’s prisons are at roughly 200 percent of capacity. Physically and mentally ill inmates sued for adequate services. Two courts over the last decade ordered improvements. When nothing happened, a special three-judge federal district court ordered that the facilities be reduced to 137.5 percent of capacity.

In reviewing the lower court’s finding, Kennedy started with what is undoubtedly his favorite constitutional concept: dignity. Prisoners, he said, have lost their liberty, yet they maintain their dignity as human beings. In fact, Kennedy asserted, the whole point of the Eighth Amendment’s ban on cruel and unusual punishment is to preserve human dignity.

Once dignity was in play, Kennedy was essentially guaranteed to hold in favor of the inmates. He has invoked the principle in a bewildering array of contexts, always with decisive force. Dignity was at the heart of Kennedy’s vote to preserve the basic abortion right in the famous Planned Parenthood v. Casey decision, where he wrote of the need to respect “choices central to personal dignity and autonomy.”