Daniel Silliman asks, in passing, “What happened in 1988?”
First hypothesis: Could be that the end of the Cold War, and the removal of the atheist enemy/competitor, made it easier for Americans in general to drift away from politico-theological prior commitments. Presumably other factors were also involved, of course, possibly in some synergetic interrelationship. Interesting that the upward slope seems to have stalled around the year 2000, temporarily reversed just after 9/11 and during initiation of the “War on Terror,” then re-accelerated through the end of the Bush years and the dawning of the “Age of Obama.”
I don’t read te graph as indcating 1988 beng anyting special – 88-90 being similiar to 74-77 . 95 is first year clearly up from the past with a clear jump in 97. The blue line’s attempt to smooth year to year fluctuations is knda misleading I think.
My reflex speculation would be the increasing levels of GenXers in the adult polling pop. as backdrop, and then whatever events you want to point to as pushing or pulling the numbers.