Romney’s father was one of the first attempts to neuter the natural born citizen clause.
He was born in Mexico.
Interesting factoid. There must have been a lot going on in Mexico around then. My grandfather applied for a VISA to Mexico in 1910 but was denied because of possible TB. He may have gone there anyway because my father was listed as born in El Paso in 1911 and no one had any connection to Texas. I’ll have to study that when time permits.