Cain/Jindal
Jindal is not a Natural Born citizen any more than Obama is or Rubio is. It takes Natural citizenship... meaning there is just US citizenship as a possiblity. That person is naturally a citizen of the US because they were born here and their parents were also citizens. John Jay spoke of this in letters to George Washington while advocating for a stronger check on the office of the Presidency - meaning that the framers of the constitution should make sure that no foreign influence be present in the highest office in the land.
Jindal and Rubio both were born to immigrants who were not citizens at the time of their birth. The same is true of Obama. We cannot allow another man into the White House who is not a Natural Born Citizen, it weakens our Constitution to the point where congress feels like it can pass any unconstitutional legislation it chooses to and get away with it. Sorry, those are both good men, but they cannot run for or hold the office.