What sort of government does not secure its own borders? A Government that wants to take advantage of cheap labor for the corporations or the government that desires to change the diversity and culture of its society? The United States is so lucky that we have a government that wants to accomplish both of these scenarios.
The borders with Mexico and Canada are large, porous, and very easy just to walk across. The issue with the Mexican border is the most obvious because of the huge Hispanic populations that have occupied the Southern States but the Canadian border is just as problematic and needs the same focus as the Mexican Border.
These borders have always been a problem for the United States. This issue has resurfaced throughout the history of this nation but never to the extent of 20 to 30 million people living in the country under the status of illegal.