Here's an archive of the old page https://archive.is/gvZ4n doesn't seem like they didn't have the ability to become citizens. Archive is from March 2019.
"Her mother, Shyamala Gopalan Harris, was a breast cancer scientist who immigrated to the United States from Madras (now Chennai) in 1960. Her father, Donald Harris, is a Stanford University economics professor who emigrated from Jamaica in 1961 for graduate study in economics at University of California, Berkeley."