I have come across this argument on many PRO CIR web sites, it follows:
There answer is:
There is no legal way provided for the typical undocumented worker to undertake our jobs in construction, yard work, agriculture, housekeeping, etc. legally. Impoverished and illiterate laborers have about as much chance of winning the lottery as they would gaining the "green card" needed to legally do our work.
The fault in their argument, if you didn't catch the 'key' word is..... "green card". In order for the "undocumented worker", other wise known as the "Illegal Alien", to legally work in the USA all one needs is a valid 'work visa', not a 'green card', unless the desire is to become an LPR or eventually a Citizen.
The work visa allows for the foreign worker to work in limited occupations and attain employee authorized benefits at a wage determined by the agreement made between the worker and the employer, or in some cases a minimum wage per hour as dictated by the Department of Labor. It also gives the worker more legal options if the employer fails to live up to its agreement. It may also burden the employer with being responsible for the worker by providing health care, housing and transportation as the H-2A visa does. The requirements of each visa type is there to protect the worker. However, this does not guarantee the employer follows the rules and in many instances have exploited the worker due to the worker not fully knowing and/or understanding their rights as workers.
The 'green card' is what one gets to become an LPR (Legal Permanent Resident) on their way to eventually becoming citizens. An alien with a green card application can obtain two important permits while the case is pending. The first is a temporary work permit known as the Employment Authorization Document (EAD), which allows the alien to take employment in the United States. The second is a temporary travel document, advance parole, which allows the alien to re-enter the United States. Keep in mind also that the status of LPR can be rescinded at any time and/or Citizenship can be denied if the LPR commits any number of revocable crimes.
Certain countries are also granted special privilege visas. The TN visa for Canada and Mexico are very under utilized and to date have never met there quotas. TN (Trade NAFTA) status is a special non-immigration status unique to citizens of the United States, Canada, and Mexico. TN status was created by virtue of the 1994 North American Free Trade Agreement (NAFTA). It allows American, Canadian and Mexican citizens the opportunity to work in each others countries in certain professional occupations. It bears a similarity, in some ways, to the H-1B visa, but also has many unique features. Within the TN set of occupations, an American, Canadian or Mexican can work for up to three years (until October 16, 2008, one year) at a time. However, the TN status may be renewed indefinitely in three-year increments, although it is not a 'permanent' visa and if US immigration officials suspect it is being used as a de facto substitute for a green card, they may elect to deny further renewals. The set of occupations permitted to petition for TN status is also quite a bit more limited than for the H-1B visa.
Spouse and dependent children of a TN professional can be admitted into the United States in the TD status.
As you can see, there are numerous ways for "Immigrants" to come here to work and/or become Citizens. It is the 'Right' of the USA to allow the type of 'Immigrant' it wants to become a legal worker or LPR/Citizen. "Impoverished and Illiterate workers" also have the possibility to obtain various visas through the H-2A, the H-2B, or family based visas. The argument then becomes, do "Illegal Aliens" desire becoming Citizens, as assumed by the PRO CIR crowd, or do they just have the desire to come here to work to better there economic status back in their countries of origin and eventually return home?