Immigration. We need to enforce the law. We need to enforce the border.
Immigration is a sensitive issue for Americans. On one hand immigrants seeking a better life are very similar to us and anyone with a heart has empathy for their aspirations. On the other hand immigrants are a significant source of excess labor causing much of the wage stagnation that we face today.
This effect has been most pronounced on those at the lower end of the wage scale - see that the loss of wages has been far worse on the part time employees in the chart on the left than on the full time employees. Part time employees have lost almost one third of their income since 1972! This is intolerable - or should have been intolerable. It is naked class warfare with the rich abusing the poor. The wages of our vulnerable population with an inadequate education have been dropping as well. This is why I am believe we should have a moratorium on immigration until salary levels have been restored to an acceptable level. We need to fully enforce the border and reestablish order.
The large corporations are trying with comprehensive immigration reform to put the same pressure on the upper middle class incomes that they have so punishingly brought to bear on lower middle class incomes. This evil plan should be resisted.
Unfortunately, you cannot enforce a rule and show mercy at the same time. It leads to chaos - which we currently have. That said, enforcement should be as humane as possible while accomplishing our end of removing the illegal population and reestablishing our boundary.