From a review, by Andrew Ferguson in the Weekly Standard, of The Roots of Obama’s Rage.
… “Wonder why Obama went to Harvard?” [the author] slyly asks. “Here is a clue: It is the leading academic institution in America. And here’s another: His father went there.” Forget that neither of these facts is a clue, technically. Surely the first assertion is enough to adequately answer the question without recourse to the second, which is simply gratuitous as well as conjectural. But [the author] always sees absence of evidence as evidence of something or other.
Let’s linger at Harvard a moment longer. “At Harvard … his real mentor was Roberto Mangabeira Unger.” Unger is a brilliant crackpot who championed critical legal studies, a left-wing academic fad of the 1980s. I’ve never heard before that Unger served as the president’s mentor. How does [the author] know it? “Obama took two of Unger’s courses,” he writes. Well, then. “Obama’s attraction to Unger’s work is obvious.” Obvious, but undemonstrated. “So what does Obama say about Unger in his speeches and writings? Nothing.” Aha! “Unger has simply disappeared from Obama’s official record, and not because his influence was minor; in fact, quite the opposite.” QED.