The Typical American, Born in the USA?

According to data from the 2012 American Community Survey, 1 in 7 American residents were born outside the United States.  About half of the foreign-born residents are now US citizens.  With the focus of "birther" conspiracists who argue that President Obama was born outside the US, there has been more attention given to the Constitution's requirement that only a natural born citizen can be President.  There are some interesting political factoids around this issue and recent US presidential elections:

• In 2012, the fathers of both the Democratic (Obama) and Republican (Romney) candidates were born outside the United States.  President Obama's father was born in Kenya.  Gov. Romney's father was born in Mexico.  
• In the 2008 presidential election, the Republican candidate, John McCain, was born outside the US. He was born in Panama in what was then the US Panama Canal Zone to American parents.  His grandfather and father at the time were commanders of the Coco Solo submarine base and a submarine based there.
• At one time there was discussion about amending the US Constitution to allow any citizen to run for President.  This discussion arose around the possibility of Austrian-born former California governor Arnold Schwarzenegger running for President.

So exactly how does one become a natural born citizen?  The Constitution does not define this term but according to Wikipedia, a 2011 Congressional Research Service report laid out the argument that this term applied to anyone who met the requirements for citizenship at birth.  Thus, that would include anyone born in the United States regardless of whether one, two, or none of the baby's parents are US citizens.  US Senator Ted Cruz for example was until recently both an American and Canadian citizen because he was born in Canada to an American mother and a Cuban father.  He has since renounced his Canadian citizenship. While his father was not a US citizen until 2005, I do not know if his Cuban-born father was a Cuban or Canadian by citizenship at the time of his birth.  Cruz could possibly file to have Cuba recognize him as a citizen too!

The second way one becomes a natural born citizen is by being born to an American citizen who is abroad.  George Romney (former governor of Michigan and Mitt Romney's father), John McCain, and Ted Cruz all fit this category.  Oddly, even if Barack Obama was born in Kenya -as some birthers claim- to his Kansas-born American mother, he would still be a natural born citizen.  These birthers obsess about where he was born but none appear to refute that his mother was an American citizen.

The US is a nation born of immigrants stretching back 10,000s of years to when the first humans arrived.  That process is not complete:  today millions of Americans are newcomers to this country.