I know you and I have thrown sparks on this topic a number of times; but realistically, I was part of that culture for my entire life until about four years ago and it's a very vocal part of the evangelical experience. There's a large focus on how the culture is moving away from a "Christian nation" (exemplified by life in the 50's, where Christian God and country were part and parcel, prayer in schools to the Christian God was a standard, mom stayed at home and dad worked and was an authority in the house, etc.) Then the 60's-70's happened (free love, drugs, Roe vs. Wade, influx of foreign culture, 'rock' music) and the cultural landscape significantly began to change. Eastern thought started filtering into the country in the 70's.
The diversity is seen as bad in the sense it confuses matters, in terms of what people should believe and how they should live; since Christianity was already at the pinnacle in the culture, any shift is a loss of conservative Christian influence.
In the 80's, especially with the downfall of the communists late in that decade (which resulted in a loss of our cultural enemy, the USSR), focus shifted onto hot button issues... abortion and gay rights. Evangelicals wanted to reclaim lost ground and win the culture wars, restoring the nation for Jesus and having us become a godly nation again. Intentions are good, but obviously non-evangelicals don't agree on this being the path that needs to be chosen. There's also a strong opinion that America's leaders need to reflect Christian values, or they will lead the country astray as has been happening over the last few decades; at least on the bottom level, on the voter level, they want to vote for someone who "seems like a good Christian" and at least can express the values of evangelical Christians. I don't know how many times I've overheard or engaged family, friends, church people, etc., on the matter; and that is the main argument used in regards to who to vote for: They vote for someone who shares the same religious beliefs. If they honor God by voting for Christians, God will honor them and fix the country.
(I'm not making this up, I am quoting what I have heard again and again from the pulpit, from church bible studies, from church conferences, from Christian books, from Christian musicians, etc.)
How much exposure to US evangelical thought do you get in Ireland? I'm not sure if there is a large influence there or not.
Anyway, thank you for explaining and clarifying what you meant.