SANTA FE, N.M. - Ever since taking office last year as the nation's first Hispanic female governor, New Mexico's Susana Martinez found her family tree scrutinized over whether her Mexico-born paternal grandfather was an illegal immigrant.
Documents obtained by The Associated Press, however, show that he was lawfully admitted to the U.S. as a permanent resident in 1918 and became a U.S. citizen in 1942 - something not even Martinez knew.
The discovery removes a potential trouble spot for someone mentioned as a possible vice presidential running mate for Mitt Romney.
Martinez was surprised at the news, but maintained that his status, citizen or not, didn't affect her political views. "I embrace lawful immigration," she said. "I think it's what makes America wonderful."
The first-term governor and former prosecutor insists she's not interested in and wouldn't accept a spot on the GOP ticket. But resolving the questions lifts a "hot potato off her plate," said Larry Sabato, director of the University of Virginia's Center for Politics.
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"It's been a controversy and it's always mentioned when her name comes up in connection with the vice presidency," he said. "Does it help her? Sure, if Romney has any interest in her and if she has any interest in accepting, if offered."
The questions arose after Martinez unsuccessfully advocated repeal of a law allowing foreign nationals without Social Security numbers, including illegal immigrants, to get driver's licenses.
News accounts about a 1930 census initially fueled the idea that Martinez's paternal grandparents had illegally entered the country.
The census used an "AL" to designate that her grandparents were "aliens." That designation wasn't an indication of whether they lawfully entered the U.S. It only meant they were not citizens and hadn't filed papers declaring their intent to become citizens, according to historians and immigration experts.
When the questions arose, Martinez couldn't turn to her parents. Her father has Alzheimer's disease and her mother died in 2006. The grandfather died in 1976.
But the AP has obtained a "certificate of naturalization" for her grandfather, Adolfo R. Martinez, dated April 6, 1942, from the National Archives Southwest Region center in Fort Worth, Texas.
His "certificate of arrival" lists March 16, 1918, as the date he was lawfully admitted to the U.S. for permanent residency. He arrived by traveling on the "El Paso Electric Railway," the document says.

