An ethnicity is a group of people mostly defined by culture and genetics. An ethnic reservoir is an ethnicity that not only is able to sustain itself, but also bleeds into the surrounding people. This means that the ethnicity must be internally conservative to have large stable families. Of their many children, some will bleed into (merge into) the surrounding people and some will remain in the group, presumably more than 2 per family so that the ethnicity can grow.
America today has 2 ethnic reservoirs - Jews and Anabaptists. As an ethnicity, Jews have gone bad since all decent Jews have already left the group. So today Jews just bleed poison into the surrounding population. Jews who merge into the surrounding population tend to be liberals or sociopaths. This means that any area with a large Jewish population will be poisoned by the Jews and will be destroyed. In contrast, Anabaptists are a good group. As they merge into the surrounding population, they improve it. I have seen this in Harrisburg, PA.
The numbers of people coming from these ethnic reservoirs is relatively small, so why does this matter? Because members of modern culture are basically like pieces of shit in a sewer - they stink and they go wherever the current takes them. They do nothing and they have no impact on anything. They are utterly worthless. In contrast, people coming from ethnic reservoirs tend to act on their beliefs and values. So they make a huge difference, and significantly impact an area where they live. Of course after a few generations, they too become worthless pieces of shit, so the ethnic reservoirs have to keep replenishing the local population.
I thought about all this today in the context of places that I should consider moving too. I don't really care about the different kinds of Americans, liberal versus conservative or whatever. They are all shit. America is only a tolerable country because of the influence that the Constitution continues to exert, to whatever limited degree, on the country. But for tolerable people, I need an area with a significant Anabaptist ethnic reservoir. Besides Harrisburg, another place I found using the Mennonite church finder is Akron, Ohio. So these are the 2 places I will look at when I have time.