One of my favourites among Obama's tricks was his use of the phrase "a young preacher from Georgia", when accepting the Democratic nomination this August; he did not name Martin Luther King. The term for the technique is "antonomasia". One example from Cicero is the way he refers to Phoenix, Achilles' mentor in the Iliad, as "senior magister" - "the aged teacher". In both cases, it sets up an intimacy between speaker and audience, the flattering idea that we all know what we are talking about without need for further exposition. It humanises the character - King was just an ordinary young man, once. Referring to Georgia by name localises the reference - Obama likes to use the specifics to American place to ground the winged sweep of his rhetoric - just as in his November 4 speech: "Our campaign ... began in the backyards of Des Moines and the living rooms of Concord and the front porches of Charleston", which, of course, is also another tricolon.
(A tricolon is a grouping of three. It's one of those sneaky classical orator tricks.)
And The Anti-Intellectual Presidency: The Decline of Presidential Rhetoric from George Washington to George W. Bush , recommended in the Guardian article, looks really promising.
Link thanks to andrewducker.