To the generation between World Wars I and II, "The Black Swan" was the title of a 1932 bestselling swashbuckling novel by author Rafael Sabatini; this book has lots of pirate and treasure ship action that still entertains today. Cutlass-wielding actor Tyrone Power and fiesty actress Maureen O'Hara brought the book to life in the popular 1942 movie.
Now that Tyrone Power et al. are nearly forgotten to the younger generation, "black swan" is known as a recent term in economics referring to a statistically-almost-impossible, but nevertheless actual event, such as the 1987 single-day-in-October stock market plunge (when there was a 23 percent drop in the Dow-Jones average).
A 2007 book by Nassim Taleb describes the phenomenon in gory detail. Black swan events happen in politics as well-typically, when a speaker solidly identified with a given ideology (and its supporting sub-principles) suddenly gives voice to the opposite.
Invariably, in the non-economic world, holding two conflicting ideas simultaneously receives the shrink-speak label of "cognitive dissonance"; the dictionary definition typically mentions the discomfort, anxiety, or mental tension in the mind of the holder.
But what about those who hold conflicting notions simultaneously and with no apparent discomfort at all?
Recently, I took note of the gentry-left exurbanites who are "into" (an overused, post-modern neologism) both smart-growth-an urban-development pattern which looks upon traditional lawns and gardens as land-wasteful sprawl-causes-and grow-it-yourself, which of course requires lot square footage for veggies or poultry-grazing or both. These exurbanites see no conflict between the two notions and give no indication of discomfort with them. Now, what about those in governance who, glibly, espouse concepts they more frequently oppose?
Historically, such statements aren't rare enough to be called black-swan events. Consider, for example, the pro forma 'I'll keep us out of European wars' promises of U.S. Presidents Wilson and Roosevelt or the "read my lips: no new taxes" pledge of President Bush I.