The Pew Research Center is out with an "Update on America's Changing Religious Landscape," and they have some truly amazing numbers. There's a lot here, I pick three points at random:

First--Look at the drop-off of millennials (-16%) compared to three previous generations (-2, -6, -8%). And Democrats are disaffiliating (-17%), but so are Republicans (-7%). But note also atheists & agnostics are increasing, but very incrementally--almost all the big gains are for the "Nones" or "Unaffiliated." These are not hardened Richard Dawkins followers, but people who have no spiritual home, and many of them don't feel the absence very much.

Second--Roman Catholics "no longer constitute a majority of the U.S. Hispanic population." Roughly 30% are Protestant, and 23% of Hispanics are religiously unaffiliated.

Third--though I think this is my interpretation more than the data (since I see no information about immigrants here)--what is so amazing is that the decline in Christianity is not caused by "immigrants," but by people of long citizenship, repulsed in part by the reactionary and racist actions of self-described (white) Christians at the decline of their hegemony. If these Christians genuinely wanted to keep America "Christian," they would be the biggest pro-immigrant people out there.  I read the intransigence of white Christians in the US to move in that direction to be further evidence that they are more white than Christian.

None of this is to say that this is an apocalypse.  In fact, seen against the long-term of several centuries, it's not clear if this isn't just a reversion to the mean.  But I'm not invested in a larger story of inevitable secularization; I'm more interested here in the medium-term changes--the slowly-dawning effect of the end of "godless communism" on the public imagination, and the consequences of strategic decisions made by white Christians in the 1970s and after, which seem to have had serious implications for religious affiliation.