Those two are pretty much the same. Certainly when I say America is a Christian nation I mean the latter. I’m sure that’s what Trump means when he says that as well.
Those are completely different to everyone who isn't in your world. Saying a country is a X-nation, where X is a religion or a ethnicity or nationality, means that it's for people who are X (and maybe not for people who aren't X), and that X has not just political influence, but laws to support that.
America is an
American nation, and during slavery it could be argued it was once a
white nation, but it was never a
Christian nation, even when nearly universally Christian, because people who weren't Christian were just as American as the others, and there weren't laws enshrining Christianity as the state religion, or funding it, etc. In fact, the first amendment banned establishing a religion.
In contrast, Israel is a
Jewish nation, because it says so in its founding documents, and many of its laws are based off of religion and to the benefit of people who are Jewish.
I would completely disagree and think you are putting the cart before the horse on this one here.
Germany was barely even a thing before Prussia went all nationalistic as an attempt to get people to unify. There was nearly no unity before that, and no one thought of themselves as German but instead as Bavarian, or Bohemian (if they cared where they lived at all). The German empire did a lot to change that by taking those influences and supporting nationalism to try to forge a national unity.
A similar thing happened with America.
Sure but America is more different in that it’s the coalescence of different European peoples into one. E Pluribus Unum and all that. You first have a shared sense of identity, THEN you form a nation around that identity. The Founding Fathers didn’t create America’s values, they are the end result of the sovereignty and will of a people forming and structuring a nation. Those values have to exist first in order to be put into the constitution, and you can trace much of the bill of rights to various incidents and culture of the American people. For example, King Philips war certainly helped to build up and drill in the importance of militia, among the many other wars fought.
Sure, the values existed before, but they weren't
American values. American values at the beginning were a distillation of the values that were shared among many of the 13 colonies as a whole, such as religious tolerance (something anathema to Massachusetts values).