Pretty much in the title, but how early in the 20th century could we see a high wave of fundementalist Christianity take hold in the US? Early Earth Creation, rejection of science, those elements, but on a much vaster support system in the states than they enjoyed OTL? Starting with a POD of 1st January, 1900, could we get things like a federal government stance towards religious views with the three bracnhes of government all working towards a particular type of Christianity?
I know some elements of this have happened in the past, but I was thinking more a strong, concentrated effort by all concerned. Any thoughts/possibilities?