Politicization of Christianity and rise of non-religion

Gallup:


Yglesias comments:

The right way to think about the growing political mobilization of Christianity is that back when Christian self-identification was up in the nineties there was nothing to mobilize. But as the number of self-identified Christian goes down, its potential as a politically salient identity goes up.

Zoomed in on the new kids:


I wonder if this rate is sustainable. If we take '69 as the start of the trend, that's +9 in 40 years. Does this mean we can expect to be 21% non-religious by 2049, more or less?

I also wonder if the trend is steeper than that. Perhaps the Internet and modern media has changed things, exposing people to different belief systems? I speak from experience, since I learned freethought online. Without the 'net I might have remained in the evangelical bubble much longer.

So it would be interesting to look at more detailed data for the last 2 decades, as I suspect the current rate of change could be greater. If we take '99 to be the start of a trend, that's +4 in 10 years. This rate would put us at 28% non-religious by 2049.