The whole debate is absurd, but since they're still going at it over at the Corner, it's worth throwing up this gem from a Slate column earlier this month:
The Constitution's rule that the president be "a natural born citizen" focuses not on where a person became a citizen, but when. To be eligible, one must be born a citizen rather than naturalized at some later date. At the founding, a special constitutional clause provided that even those who had not been citizens at birth could nevertheless become president, if they were citizens circa 1787. Thus, Alexander Hamilton, born in the West Indies, was clearly eligible. All those already in America in 1787 could be trusted; but the framers fretted that an Old World earl or duke might someday sail across the Atlantic with a boatload of gold and bribe his way into the presidency. (Rumor had it that George III's second son, the Bishop of Osnaburgh, would soon head this way.) Thus, the "natural-born" clause's main target of concern was not immigrants generally, but wealthy European aristocrats who might wreak havoc in an America lacking strong campaign finance laws.
How do you like that...it's all about campaign finance.