Ted Cruz Citizenship Timeline: Ted Cruz is Canadian at birth. Period.

[starroute]

57. This is why I said I'd seen earlier versions and they hadn't changed much

There's a chart of the changes at http://www.greencardlawyers.com/citizenship/citizenbybirth.html#Chart%20to%20Determine%20Citizenship%20Rules

The 1952-86 version says, "If one parent is a U.S. citizen, the U.S. citizen parent must have resided in the U.S. for 10 years, at least 5 of which were after age 14."

The 1986-present version says, "If one parent is a U.S. citizen, the U.S. citizen parent must have resided in the U.S. for 5 years, at least 2 of which were after age 14."

There were also provisions added in 1986 concerning children born out of wedlock, but I don't see any other changes. A detailed rundown can be found at http://www.state.gov/documents/organization/86757.pdf

So as far as I know, the language about "acquiring" citizenship at the point of becoming a legal permanent resident remains unchanged.