Yes, I agree – there is no “structural” anti-Christian bigotry here. The phenomenon arises from the demographics alone.
I’ve already touched on what I suspect is the key element underlying American Christians’ claims of persecution: their declining influence. While they remain numerically superior and politically powerful, there’s no real debate that the last fifty or so years have seen the dominance exercised by American Christians erode. It is that delta, that change, that I suspect they are reacting to.
As you say, this doesn’t mean this is a serious ill to be remedied, since their absolute position remains so advantageous.
And your effort to draw an analogy between liberals on the SDMB and Christians in American society is, in my opinion, spot-on. Liberals may get grief here from the occasional upstart, but can take solace in a ready-made bunker of allied support. They may experience persecution, yes, but it’s not something that should concern a neutral observer, because the persecution has no real threat behind it.
In American society, Christians enjoy a similar – indeed, perhaps even greater – advantage in terms of numbers and political power. They certainly suffer some hostility and ill-treatment, and can fairly be said to experience persecution. But it’s not the kind of treatment that should engage a neutral observer to worry, because society as a whole remains comfortably monolithically Christian, and the persecution in question will not lead to any real threat.