In the case we are talking about a dual citizen is not just British subject. Just because the country you happen to be in allows you to claim citizenship that doesn’t not make you a natural born citizen of the US if your parent is a US citizen.
I never said it did. You initial question was "If my mom, a US citizen, was in England on vacation when I was born, would I be an English subject". The answer was yes, prior to 1983, you would be a British subject ( no such thing as an English subject ). I didn't say anything about being a natural born US citizen. As far as being a British subject, in the circumstance you presented, citizenship was bestowed automatically- there was no need to claim it.
CRBA?
Today yes, but not when Cruz’s mom gave birth to Ted in Canada, she would had to renounce her US citizenship to receive Canadian citizenship. She voted in at least one Canadian election as a Canadian citizen, that is on the record.
“Just because the country you happen to be in allows you to claim citizenship that doesn’t not make you a natural born citizen of the US if your parent is a US citizen.”
Double negative, but yes that is true. But being BORN in Canada to a Cuban citizen father means you are NOT a “natural born (US) citizen on TWO counts. Regardless whether Canada gives you their citizenship or not.
It is not about Ted Cruz being a Canadian citizen or a Cuban citizen, it is about his UNITED STATES CITIZENSHIP status as an Article II “natural born citizen”, which he definitely is NOT!