If all non-white people think alike, how can they split their vote?

Today's Times has a hillariously horrible story on the rising tunrout of Native American voters across the country. In a classic example of the subtle racism that plagues much reporting in America, the article wonders why Natives in tribes like Connecticut's Mashantucket Pequot vote and donate Republican, while those on South Dakota's Rosebud and Pine Ridge Reservations and on the Navajo Nation are Democrats. All Native Americans must be the same, right Bob, so how come they vote differently. Question: would you find it a little weird if the New York Times published an article wondering why a group of white people split their votes evenly while only quickly mentioning that the half who vote Republican are stockbrokers while the half who vote Democrat are steel workers? Hmm, I wonder what the reason is?
The fact is there are some tribes in this country that have becomeif not rich, than relatively wealthy, largely through casino gambling. These tribes tend to vote Republican. Reservations like those in South Dakota on the other hand are the poorest places in the nation, with Pine Ridge being the only area north of the Mexican border that classifies as level 3 on a UNESCO poverty scale. These groups vote overwhelmingly Democrat. Now is the reason all that confusing? I guess so, because non-white people have to have different reasons for voting than white people do, I mean, it's just genetic.