Collectively on the National scene? No. But within their respective individual states, yes, particularly in major Indian states like Oklahoma, Arizona, New Mexico, South Dakota, and Alaska, where larger, politically powerful tribes like the Cherokees, the Navajos, the Hopis, the Sioux, and Alaska Indians can vote in blocs, thus making an impact on state and local elections.
Thanks. I think you have answered my questions, or, at the very least, given me reason to research more.