I find it funny that this issue has only come up in regard to Republican candidates, Goldwater, McCain and now Cruz. But the difference is both Goldwater and McCain were born in a US territory. Goldwater before AZ became a state and McCain on a base in Panama. However Ted Cruz was born in a foreign country that being Canada.

The founding fathers wanted to ensure someone would not be born outside the US and become the President so they said Natural Born Citizen.

Sounds like Ted Cruz's birth is what the Founding Fathers were worried about.