It is important for voters to know that Cruz was a Canadian citizen until just a year and a half ago.
It is important for voters to know that Rubio probably was also a born Cuban citizen since neither of his parents were US citizens when he was born.
Forget the constitutional discussion for a moment. Don’t worry about what is legal or not legal.
Just add those bits of information to your list as you process everything else that needs to be processed when you choose a candidate.
Cruz was born in Canada and was a Canadian citizen.
Rubio’s parents were both born in Cuba, had not become US citizens, and it is possible that Rubio is a dual citizen with Cuban citizenship. No one has clarified that yet.
Interestingly, I looked up Cuba's citizenship laws to see it Ted Cruz might be a triple citizen, not just a dual citizen. I learned that any Cuban citizen who is abroad who did not support the Castro Revolution has lost the right to descend Cuban citizenship onto a child born abroad.
Cruz' father fled Cuba after the Castro revolution, so it is likely that he was Constitutionally barred from passing on Cuban citizenship.
Rubio's parents, however, left Cuba three years before the rise of Castro, and his mother made four trips back to Cuba since then. It's possible that Rubio's parents did descend Cuban citizenship to Rubio when he was born, as they had not yet become American citizens.
-PJ