“In multiracial societies, you don’t vote in accordance with your economic interests and social interests, you vote in accordance with race and religion.” – Lee Kuan Yew, founder of modern Singapore.The article goes on to describe tribal warfare on the Los Angeles city council.
People are invididuals, of course, and can make up their own minds about political preferences. Some do. Most don't.
I don't think democracy makes any sense in Third World countries dominated by ethnic conflict.
In the USA, some ethnic groups vote as a bloc. Notable examples are Blacks, Jews, and Mormons. For those groups, I don't think it makes any sense to pay attention to individual beliefs. They are just going to vote as a bloc anyway.
Other groups like Whites, Catholic, and Protestants, do not vote as a bloc. Some vote Republican and some vote Democrat. American government works fine for those groups, because they try to vote what is best.
Open borders policy is incompatible with American politics. It just brings in people unsuited to the system.