Michael Barone
observes that "Every 16 years--in 1976, 1992 and now in 2008--American voters have seemed less interested in experience and credentials and more interested in a new face unconnected to the current political establishment" and then goes on to wonder "What can explain this 16-year itch?"
I'll endorse the
Nyhan hypothesis: it's random chance. This is an extreme example, but a strikingly large quantity of political journalism seems focused on this kind of silly analytical error.
This article available online at:
http://www.theatlantic.com/politics/archive/2008/01/fifteen-years-till-his-liver-exploded/47747/