Another death senence overturned

The Supreme Court overturned another Texas death penalty because jurors did not consider the killer's learning disability and other evidence. Only Scalia and Thomas dissented.

The ruling cited an similar ruling in the case of another Texas death sentence from five months ago. It is interesting to note that in that case, Rehnquist had joined Scalia and Thomas in opposing the decision. This time he chose to support the decision.

From what I can tell, the two cases are very similar, so Rehnquist's decision is curious to me. It could just be that he is keeping with precedent, or that the circumstances in this case differed slightly. But I wonder if facing his own mortality in the form of thyroid cancer might have had an effect.