That is because there is a large, low-skill labor segment that needs filling, American citizens won't touch it with a ten-foot pole (when was the last time you saw unemployed inner-city Americans looking for tomato picking work?) and there is no legal way to meet the business need.
So, American business violates the law and Congress smiles and looks the other way.
See my Post 50.
Also, Polybius, we passed Prop 187 almost a decade ago here in California, denying welfare benefits to non-citizens. MALDEF took the law to court and defeated it!
Which will mean that, when other states crack down, you will get a flood of illegals into California and Californians will be more choosy in who they vote for and what kind of Judges they will appoint.
To solve any problem, you need to identify the root cause and address it.
The root cause is that it is way too easy for illegal Mexicans to get illegal jobs and legal welfare in the U.S.
While in the Yucatan this summer, a Mexican told me that the "norteamericanos" were giving "mixed messages" about illegal aliens because they say they do not want illegal workers but, once they get to the U.S., they turn right around and even issue them drivers licenses!
"The root cause is that it is way too easy for illegal Mexicans to get illegal jobs and legal welfare in the U.S."
100% agreed.