The Times has done fascinating work on statistical correlations for populations in Trump-favoring counties. Second from the top in strongest correlations (after "White, no high-school diploma") is "'Americans' - Percent reporting ancestry as 'American' on the census." At the bottom of the list is a strong negative correlation, "White Anglo-Saxon Protestants - Whites with European non-Catholic ancestry." So it's not the WASPs. And it's not people who identify their ancestry with specific European countries. It tends towards Catholic ancestry. It's not going to be Irish or Italian or Polish or French, since the Irish, Italians, Poles and French proudly claim their ancestry.
What European ancestry have Americans disowned after going through two World Wars? It's German-Catholic-Americans who pretend to be simply "American" who are the core of Trump's support. That's who the WASP Republican establishment got in bed with. And due to the strong authoritarianism that's always been strong at the intersection of German and Catholic cultures, that's who is drawn to Trump -- himself a German-American. This is the population prone to fascism in America. Is there any way, in their own culture's terms, to reach them and turn these German-Americans away from this dark path?