LTE: Immigration and the Free Market
Immigrants do not come to America to take jobs from citizens, much less "steal" them. They come here because American employers hate the free market.
In a free market, when there are "jobs Americans won't do" employers would keep raising the pay for those jobs or improving working conditions until they found what those jobs are worth on the open market. In a free market, no one decides what things are worth on his own. It must be done by negotiation between supply and demand.
Instead, American employers think they have a unilateral right to determine what they'll pay for labor, and if the American labor market doesn't agree with them they'll dilute that market with labor from illegal immigrants. "Guest worker" programs just make the dilution official.
Employers are the ones driving illegal immigration, and any solu tion to the problem has to hit them the hardest because they're the ones with the power.