Labor and workers are now the stepchildren of philosophy and religion with very little said about the degradation of human dignity in the workday.
Some approach the illegal immigration problem with a plantation owner mentality applying band aid solution to the effects of Free Trade and Globalization without looking at the causes of misuse of labor and workers in the global economy. 
The US Federal Government first sponsored the moving of factories outside the USA in 1956. It evolved into the Maquiladora factory program in Mexico using impoverished workers to supply American consumers with cheaper goods. However, this impacted the middle class in the USA with millions losing their  jobs with a new working poor class created in the USA.   After NAFTA trade agreement confirmed what was going on for many years, the  process speeded up. After NAFTA was passed, the number of factories moved to Mexico doubled to more than 4000 factories.  The average wage in the Maquiladora factories was 62 cents an hour.  President Bush says the Mexican workers come to the USA to take jobs Americans will not do. He forgets to add that there are jobs in Mexico, Mexican workers will not take in former U.S. factories moved to Mexico.

Of course workers in both countries are seeking jobs that allow for at least subsistent living wages.  In the U.S. we have  working homeless  people who work but can not afford shelter.
In Cleveland Ohio, the Metropolitan Boards of Education report a massive increase in students of families who are homeless.

Bishops and other  people of good  will ignore this and do not realize that they are taking part in degrading human dignity in the work day when the protect the current  working environment in both countries with workers competing for the same jobs down to the levels of impoverished workers pay.

For more see the many related articles at http://www.therationale.com/  http://tapsearch.com/tapartnews/
http://www.bizarrepolitics.com/
http://tapsearch.com/id40.html/
http://tapsearch.com/flatworld/