America's Founders were concerned about invasion. It was mentioned it four times in the Constitution, though the term was never explicitly defined.
Ben Franklin's words ring just as true today as they did when America was founded.
The December 13, 2012 article CAIR-Michigan Goes After the U.S. Constitution reports that:
Two law professors, including one who served in the Bush Justice Department, have published a paper charging that President Obama violated the Constitution with his directive to law enforcement not to deport illegal aliens.
