One of the often overlooked problems of illegal aliens is the health of the nation. Many of these people bring desease and their low quality of life breeds even more. These kind of people need more health care than those that have maintained a higher quality of life.
It not only puts us at risk, but drains our health resources as we take care of all these sick and needy people.
Speaking of which, check The Miami Herald. They had a really good article today on the possibility that the average life span could fall this century.