“Cuba at the time of his parents birth, had a protectorate status of the US from the Spanish/American war.”
If that isn’t a strech!!!!!
Not really. Rubio's parents were born in 1927 and 1931 in Cuba, however Cuba during that era, was a US Protectorate from 1901-1934 under the Platt Amendment.
It may not be a 'bingo there is the answer' but it does give a different legal foothold.