@ebrown p,
I would add, it is the enforcement that is the main problem with our current immigration system.
Every time we have tried to harsh punishments to stop a basic human impulse, it has not only failed, but it has failed with big social costs. We tried to end homosexuality with harsh punishments. We tried to end abortion. And, we tried to end race mixing. We even tried to stop people from drinking beer. In each case the result was social unrest, prejudice and organized crime.
The immigration system we have now is based on punishing individual people who are mainly trying to get the priveldedges that we all take for granted (thanks to nothing more then where we were born). There are many reasons from a better life for your children to the desire to be with your US citizen family.
The current punishment is based on things that should make anyone with a heart shudder. Families are being broken. The poorest of the poor are being jailed (at a big financial cost to their already impoverished family) before they are deported (a double dip of cruel punishment).
You will say correctly that they broke the law-- but there is also the point that the punishment should fit the crime. Breaking families and further impoverishing poor wage earners hardly seem reasonable for the crime of crossing a border.
A human immigration system will lessen the punishment on workers and families, and increase the punishment on employers.
Cracking down on individuals (who are already treated pretty badly) is both cruel and ineffective.