Isn't Cruz's situation exactly the same as Zero?
No. Obama's story (that the left has accepted) is the he was born in Hawaii to a mother who was a US citizen but whose father never was.
Ted Cruz was born in Canada to a non-US citizen father but a US citizen mother.
The left made a big deal over the fact that Obama was born in the US, and that the 14th Amendment made him a citizen at birth. Their primary argument was based on the 14th Amendment and the Wong Kim Ark SCOTUS decision. In effect, they were arguing that NBC = born on US soil. So they'll have no problem with self-contradiction when they argue against Cruz's eligibility.
“Isn’t Cruz’s situation exactly the same as Zero?”
No, it is not the same situation. Obama’s mother was a minor, not emancipated, and not lawfully capable of transmitting her own U.S. citizenship to her child, regardless of where the child was born. Furthermore, there is still no credible evidence available to demonstrate his birth was within Hawaii or the United States. There is credible evidence Obama is an illegal alien who obtained a U.S. Passport by fraudulent means. It appears likely there may have been a fraudulent application for an Hawaiian birth certificate, but the publicly disclosed documents puporting to be evidence of such a birth certificate are now proven to be frauduklent forgeries according to current law enforcement investigations.