The comments at the article site seem to focus on the notion that a native-born citizen is inherently more loyal than one born in another country, even if he moved here as an infant.
This seems a rather silly argument, as we have massive evidence that very large numbers of indisputably natural-born Americans are aggressively anti-American.
Left wingers like yourself admire our enemies; such as cuba, iran, syria, venezuela, etc; but even those genocide countries will never allow a foreigner to be their president.