When I say the government should not interfere with people coming to the U.S. to look for employment, I am not saying the government should guarantee anyone a job; I am only saying that the government should not interfere.
The problem, UP, is that you are suggesting that the government should have no role - including that of defending our borders. This is one of the many reasons for which I do not subscribe to libertarian principles. I agree that government should be limited - and certainly FAR more limited than it currently is. But I do not believe government should be non-existent. It is not hyperbole to compare the gradual assimilation of barbarian groups into Roman society (which ultimately overwhelmed the empire) to the gradual (but rapidly increasing) assimilation of a culture which includes many who think they ought to "retake" Mexican lands ceded a century and a half ago. I don't take that as so big a literal threat as some of the more alarmist elements out here, but I do consider it.
Here is one simple statistic that brings this issue home to me. This past summer, I volunteered to become a literacy/ESL tutor (though an unexpected change in my life made me have to drop it.) I began the training and we were told that this year, in the city of Harrisonburg, 47 percent - almost half - of the Kindergarten population were ESL students. This is a rapidly growing city and much of the growth comes from immigration. Not all are Hispanic. We have Russians, Kurds, Bosnians and other ethnic groups. But the vast majority is Spanish-speaking. This is no longer the small city it was a decade ago when I moved here. We are rapidly growing and have even managed to capture some dubious recognition. Two of our city's fine citizens have been featured "guests" on "America's Most Wanted." Reader's Digest prominently mentioned an MS-13 murder victim from our shady little valley in a story about growing gang threats. The DEA has identified this city as one of the major sources of Crystal Meth on the East Coast. Some DMV workers were busted shortly after 9-11 creating false IDs and Driver's licenses for illegals. This city, which was safe and quiet only a few years ago, has become a dangerous place with muggings and other violent crime becoming commonplace. Not all of this, of course, is solely due to immigration. But a lot of it is.
It is not a basic right to enter someone else's lands, homes or property and take that which does not belong to you. Once having been given legal permission to enter this nation, I say make yourself at home. But until that is done, take yourself BACK home. If the government has a basic function at all, it is the protection of the borders. That's an extension of my right to secure my home from invaders. You have the right to travel from place to place, but not to enter my place without my permission. That's because of my inalienable property rights. Same goes for my borders. The government is not, as you ask BT, a landlord. Rather, it serves the function of a guard, hired by the landlord (in this case the people of the United States) to provide security for the property owned by the landlord. Violating my borders is NOT trespassing on the government's land. It is trespassing on MY land. The purpose of government is not to become some bloated bureaucracy. But it IS to provide security to those who put the government in place. That's a fundamental part of the contract of government and people. There really isn't a heck of a lot more a government should do. But it should darn well do that.