In El Paso, he worked as a taxi driver. The governor said he was estranged from his family of five children, who were born in the city. His wife died in 1934 at age 31, and the children were raised by the wife's mother — Martinez's maternal great-grandmother.
Historians say immigration between the U.S. and Mexico was largely free of restrictions in the early 20th century. Mexicans could easily declare at checkpoints whether their stay was temporary or whether they intended to become permanent U.S. residents.
The grandfather and his wife paid a "head tax" in July 1918, which was required of immigrants. He obtained a border-crossing card in 1921, making travel easier during World War I, said Marian Smith, a historian at the U.S. Citizenship and Immigration Services.
He was 48 when he became a citizen. It's unclear why the grandfather waited for more than two decades before becoming a citizen.
Smith said many longtime immigrant residents decided to complete the naturalization process after a 1940 law that required the fingerprinting and registration of non-citizens living in the U.S. Another possibility was his marriage in 1941 to a U.S. citizen.
Guadalupe San Miguel Jr., a history professor at the University of Houston and scholar of Mexican-American history, considers it unfair that a Hispanic elected official like Martinez is subject to scrutiny and possible criticism for the immigrant roots of her family.
"It is definitely an anti-Mexican immigrant strain of thought that is being applied to her," he said.
Sabato said questions about a candidate or elected official's family history are fair game in politics, and doubts that she would suffer much damage even if her family had entered the country illegally.
"Maybe it would be more fair if everybody were subjected to the same scrutiny," he said.
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