You can call me a birther if you want to, but neither Rubio or Cruz are qualified to be president. Neither are "natural-born" citizens. Rubio, although born in Miami has Cuban parents. Cruz, born in Canada, had only one parent who at the time of his birth was an American citizen. I would call them naturalized, but not natural-born. Another way to be naturalized is to be born in a foreign country to foreign born parents and go through the naturalization process and pay the fees. Natural born means born on America soil ( or an American military base or an American embassy) to American citizens.

Consider Deut. 17:14-15 14 ¶ When thou art come unto the land which the LORD thy God giveth thee, and shalt possess it, and shalt dwell therein, and shalt say, I will set a king over me, like as all the nations that are about me; 15 Thou shalt in any wise set him king over thee, whom the LORD thy God shall choose: one from among thy brethren shalt thou set king over thee: thou mayest not set a stranger over thee, which is not thy brother.

I realize times have certainly changed since the Constitution was written, but I personally don't believe the founding fathers intent was to have naturalized rather than natural born citizens be president.