George on Amar and the "Unwritten Constitution"

Our fellow blogger Robby George has a very interesting review of Akhil Amar's new book, "America's Unwritten Constitution," in the pages of this week's Times Book Review.  Robby's review is, on the whole, positive.  Here is a bit from the conclusion:

Almost everyone agrees that the Constitution includes whatever its text logically requires or more or less clearly implies. More provocative but also persuasive is Amar’s contention that it includes principles inferred from how the written Constitution was enacted. But can constitutional principles, even broadly construed, include some derived from George Washington’s presidency, or Martin Luther King’s “I Have a Dream” speech, as Amar suggests?

Amar allows that parts of his unwritten constitution are “not on the same legal level” as the written one. But that raises the question: What in general does it mean to say that some principle is part of the unwritten constitution? Does it constrain government actors as stringently as principles of the written Constitution do, or less so? A more unified, detailed account of the unwritten constitution’s function might bolster Amar’s bolder claims — or qualify them. It would help us to see more clearly the boundaries of the constitutional landscape that Amar helpfully sketches, a landscape neither fully lighted by the text nor darkened by “penumbras, formed by emanations.”