It is estimated that as many as 40% of the illegal aliens in our country now are here because they came legally and then didn't leave. Through Visa's, whether it is tourist, student or work, we have given these people the opportunity to come here and agreed to leave when their time is up. Instead of tracking these individuals on when they come and when they leave, our government has just left it all to trust.
As Michael Cutler points out, all of the 9/11 hijackers came into the United States through ports of entry.
Here we are, approaching the 14th anniversary of the first attack on the World Trade Center on February 26, 1993 and more than 5 years after the attacks of September 11, 2001, and still our nation's immigration system lacks meaningful integrity, which thereby imperils our survival and our nation's security. America is no longer the "Can Do!" nation that exceeded the goal established by President John F. Kennedy’s target of January 1, 1970 for sending men to the moon; that responded to the attack on Pearl Harbor, at a time when it was not a super power, by constructing fleets of new battleships, aircraft carriers and various airplanes including new fighter planes and bombers; that put many new submarines to sea and even developed, constructed and deployed the world's first nuclear weapons. The United States of America did all of these things and much more in fewer than four years!
Four years on after 9/11 our politicians were still bowing to illegal alien supporters and putting us in danger because of it -- and they continue to do so. Rather than risk offending a group of people who aren't even supposed to be in our country, our President and many other politicians in this country, just couldn't look past the support and money they could get from illegal alien lobbying groups and businesses in order to protect the nation.
As Michael states above, we put a man on the moon and developed an atomic bomb in under 4 years, there is no excuse why we can't track people who come to our country and assure that they abide by the rules of the agreement.
It's a total disgrace!