The Bush plan for a guest worker program mirrors the old Bracero program and the recent H1-B visa program for high-tech workers: a business-friendly system of inviting labor into the country who can be deported when their labor is no longer needed. Immigration Plan Chains Workers by Rosalio Muñoz
The most infamous legacy of the Bracero program, aside from the death and exploitation common to all labor-import situations reminiscent of slavery, were the hundreds of millions of dollars of back pay that were deducted from worker's pay by American banks. (An old SFBG story about this.) Bracero Class Action Lawsuit.
In the post-dotcom era, high-tech workers have found themselves in a situation of watching jobs "offshored" to other countries. During the boom, tech workers were allowed into the country via the H1-B visa program. Afterward, the workers were sent home, then, the jobs were sent along with them. The high-tech sector is woefully un-organized, and many workers espouse a "Libertarian" pro-business political line that rejects regulation and collective bargaining in favor of "free markets", "freelancing", "small business", and "individually negotiated contracts". Lacking the political will for self-organizing, the tech workers find themselves atomized and ripe for exploitation. See: WashTech