Rubio was born here so he is a natural born citizen. The idea that you need to be born here and that both of your parents have to be citizens is incorrect. No court has ever held this to be the case.
Second, if we go by your equation and Rubio runs, wouldn't the issue go both ways?? Obama’s parents weren't both citizens when he was born here either. So for birthers like yourself, wouldn't you want this as it would raise the eligibility question to both candidates.
Barack Obama is patently ineligible to be the President as both of his parents were not US citizens. He may also still be an Indonesian citizen and not even a naturalized US citizen. He is totally aware he is ineligible which is why he has sealed all of his records. By some patent unspoken agreement the two political parties and both houses of Congress circumvented the Constitution and allowed him to be elected. This is a mistake that must not be allowed to be repeated.
The Supreme Court has already ruled in 4 separate cases over the years that a Natural Born Citizen is a person born in the US of two US parents. There are currently numerous lawsuits such at the one in GA challenging Obama’s eligibility to be on the 2012 ballot. We do not need the chaos that will ensue if Newt or Mitt try to run Rubio as VP this year.