I think its funny that there are low paying jobs available that americans won't do, but no legal way to fill them with people from other countries. The only legal temporary employment visa you can get is with agriculture.
For family sponsered visas, currently, if you are from mexico and are a citizen, and you are trying to get an unmarried son or daughter in the country, the U.S. immigration is working on application filed before 15 october 1992. The most recent date is spouses and children of perminent residents, 1 June 2006, that is across the board (any country). This means that the person would have to have gotten their green card before this date, and had their family apply before June 1 2006. This date moves at a glacial pace, so basically these peoples spouses and children have been waiting 4 years since they applied, and probably much longer than that (another 5 years) to get in the country legally. The fees for this are a huge barrier as well. Over $1000 to apply for a green card, another $400-$500 to see the civil surgeon and get a physical, all to have you wait for years.
For employment based visas, the dates range from 2001 to 2005. So if you applied before those dates, then they will start to process your application.
This is one problem, far be it for me to criticize the U.S. and its immigration policy, but this was not how it was presented to me when I moved here. So there is one problem.
You also have businesses who employ these people, and good americans who do not want to pay more to have their lawn mowed or for restaurant food, so the employers go for the cheapest labor to keep the price down. They are also spending money lobbying the government to keep the rules the same.
The I.R.S., immigration, department of labor, social security, and the department of state are alll involved in processing an immigrant. They don't talk to one an other or co-ordinate information. I don't understand why, perhaps an american can ellaborate on the thinking here. Anytime I speak with a neghbor or friend about this, they don't want them to communicate, they think its a bad idea.
Lastly, my wife was a police officer in Canada. She arrested people and when they couldn't produce I.D., she was on the computer looking them up on the interpol database and they got their ass shipped out of the country. Or they were confined to the ship they were in port on. She certainly didn't randomly ask people for their papers, which I think is oppressive. And if you were employing someone, they had to check out with the government database, or if you went to the doctor, you got found out.
I don't understand why the U.S. doesn't make the border guards do their job, or give them the resources to do it. Or crack down on companies that hire people illegally. Or fix their own internal problems to process applications in a timely manor. Until these things are fixed, you are going to get illegal people in this country, and a fence ain't keeping them out.