J. Balkin on the decision:
"Although the court reaches the right result-- that the program is illegal, much of the opinion is disappointing..."

But I think the court's rhetoric will have an impact.

We must first note that the Office of the Chief Executive has itself been created, with its powers, by the Constitution. There are no hereditary Kings in America and no power not created by the Constitution. So all "inherent power" must derive from that Constitution."

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update
One can argue without being either a cynic or a 'realist' that politics helps to define or redefine the sort of arguments a reasonable person may be supposed to engage.

I don't want to push this thought too much. maybe I have, We'll see.