I don't think he is eligible.
And Obama birthers cannot state that Cruz is eligible unless they want to directly contradict themselves.
Both had non-citizen fathers
Both had American mothers
Obama was born in a U.S. state
Cruz was born in a foreign country
There's no way to claim Cruz is legitimate while Obama is not.
This is false. That is to say, you don't rightly understand the matter. Obama had to be born in the United States in order to be a natural-born citizen. Period. His mother did not have the required period of residency in the United States past a certain age at the time of his birth as was required by the law that prevailed at the time of his birth. That's why she stayed in the United States until after he was born in order to secure his U.S. citizenship at birth. The birthers are out of their minds. He was not born abroad.
Cruz's mother, on the other hand had the required period residency in the United States past a certain age under her belt when he was born abroad. So he did not have to be born in the United States in order to be a natural-born citizen, he just needed to be tied to the soil of the nature through her.
The nationality of their fathers, as far as their U.S. citizenship is concerned, is utterly irrelevant. However, had Obama been conceived just a few months earlier, she could have given birth to him in Nigeria with the required period of residency past a certain age under
her belt too, and Obama would have been a Nigerian citizen and a natural-born U.S. citizen at the moment of birth.