Ana Maria Gallegos’s family has called this part of the West home for centuries. But after growing horrified by the resurgent racism she has seen across the United States, she reviewed her options and decided on a plan: emigrate to Spain.

Ms. Gallegos joined a growing number of Hispanics from the United States benefiting from a 2015 Spanish law seeking to atone for one of the grimmest chapters in Spain’s history: the expulsion of thousands of Sephardic Jews in 1492. The law offers citizenship to descendants of those Jews, many of whom converted to Catholicism but secretly adhered to Jewish traditions as they settled in New Mexico and other frontiers of the Spanish Empire.

“I had neighbors start spewing the same racist talk as the president of the United States,” said Ms. Gallegos, 54, a court reporter raised here in a Catholic family. “All this hatred just scared the wits out of me, but fortunately I had this ancestral connection.” She left New Mexico this year with her husband and 12-year-old daughter, moving to Málaga in southern Spain.