The difference is the claim against Obama. The claim is that Obama’s mama birthed Obama overseas BEFORE she had met the years of eligibility requirements of the law. She was very young.
Cruz’s mom did meet those years of eligibility requirements. She was already a college graduate plus.
So far as Ted Cruz being a Cuban citizen is concerned, it is not likely. Cruz’s dad became a Canadian citizen, and at the time, Canada was strongly encouraging its citizens not to have dual citizenship. Rafael Cruz probably renounced his Cuban citizenship on becoming a Canadian citizen. We know he renounced his Canadian citizenship on becoming a US citizen.
Cruz need not resort to a statute for US citizenship, does he? If so, it means Congress could, by changing the statute, effectively amend the constitution. A statutory change would redefine the meaning of "natural born citizen" under the constitution.