FLAGSTAFF, Ariz. (AP) — Jon Rios traces his ancestry to the Pima people of Arizona, but he has no tribal enrollment card and lives hundreds of miles away in Colorado.

He has no interest in meeting any federally imposed requirements to prove his connection to a tribe. If anyone asks, he says he's Native American.

"I'm a little bit like Elizabeth Warren. I have my ancestral lineage," Rios said, referring to his affiliation with the Pima, also known as Akimel O'odham.

The clash between the Massachusetts Democratic senator and President Donald Trump over her Native American heritage highlights the...