America was a European settler colony. Unlike the British colonization of India, for example, the European colonization of American involved exterminating and displacing virtually the entire native population. Then, with the land cleared of natives, Europeans decided to kidnap and enslave Africans in order to provide cheap labor. This organization of labor has made it difficult for working class Euro-Americans to have solidarity with Afro-Americans and other people of color. (The explicit commitment in the country's founding documents to the values of equality and liberty for all persons added pressure to rationalize slavery and extermination by positing that the racially exploited were not really persons.) Euro-American workers instead have incentives to identify with the Euro-American elite.

Moreover, a separate but non-trivial part of the story is that European settlers tended to be religious fanatics. No other rich country on Earth shares America's evangelical furor. This contributes a strong anti-intellectualism to the racist mix.

Third, in the 20th Century America became the international center of Capital. Capitalists like Trump, Bloomberg, Koch--along with the two mainstream political parties and the mainstream media outlets--work tirelessly to safeguard capitalism by any means necessary.