I can see that your view of "Christians" appears to be quite different from reality. You speak as if "white" and "Christian" are somehow joined at the hip and thus inseparable....apparently to paint christianity as "racist". Facts don't support that though Vincent. Consider these;

According to PEW Research data there are about 2.2 billion people who self-identify as "Christians" in the world. 36% of that total are in the US, 26% Europe, 23% sub-Saharan Africa and about 13% Asia. Pretty racially diverse. https://www.pewresearch.org/religion/2011/12/19/global-christianity-exec/

In the US 70% of whites identify as Christian, 79% of blacks, 34% of asians and 77% of latinos. Again, pretty racially diverse. https://www.pewresearch.org/religion/religious-landscape-study/compare/christians/by/racial-and-ethnic-composition/

That book you reference, "Christian Nationalism" does not represent core Christian thinking. It is at best a fringe position. Just because someone publishes a paper back on Amazon does not make mean it represents every Christians position or thinking. Far from it.

Another inconvenient fact is the birth rate. Fertility rate across all races/ethnicities in the US has been declining for years. You seem to suggest that white's are reproducing faster than other races. But that's not true.

According to government data, 2020, birthrates in the US were highest for Native Hawaiians and Pacific Islanders (65 / 1000 women), American Indians and Alaskan Natives (58/1000), Hispanics and Latinos (56/1000), "some other race" (56/1000), Black or African American (54/1000), Whites (51/100), "Two or more races" (51/1000), "White alone, not Hispanic or Latino" (50/1000) Asian (50/1000). These numbers are verified by several differrent sources, but here's one that most people would trust. https://www.statista.com/statistics/241514/birth-rate-by-ethnic-group-of-mother-in-the-us/

Be well....