Part of the problem is that we have been too sucessful
Look back in time, I know it is a difficult thing for many, especially those on the younger end of thing to think that anything in the past actually has any relevance to their lives, but try anyway.
Was there an illegal immigration problem in the past? And was it foreign workers "stealing" American's jobs? Were there jobs that Americans "won't do? Not really, or not much, if any. Look back to the Depression years, before there were social programs, and you will see that there were no jobs Americans wouldn't do, and for next to nothing for wages. Because the alternative was exactly that, nothing. Soup kitchens and churches meant few people actually starved to death, but beyond that, you had to work. Handouts were demeaning. Like unwed pregnancy, in those days if you couldn't provde for yourself and your family and had to accept charity, there was a social stigma attached.
Jump forward to the post war boom economy, and see the children of even those doing well working for their spending money. Summer jobs, farm work, paper routes and selling cookies. All this and more as an introduction to working class life. The parents, who remembered when times were bad, generally insured that the children knew what it meant to have to earn a living.
Jump forward some more, and see the children of the well off no longer working, but playing, using Daddy's money to go to college, and for their fun. See social programs, begun with the best of intentions, to help the poor, ballooning into huge entitlements, because even the poor have votes.
See wages and benefits fought over and won by previous generations of union workers now mandated by law for everyone.
Anybody out there know why businesses offer health care insurance for their workers? Anybody know when this started? And why? Today many people think it is their "right" as full time employees, but does anyone remember how it come about that workers got not only wages but benefit packages as well?
I'll give you some time to answer.
Foreign labor doing the jobs that American won't do? Yep. Kind of. They are doing the jobs that Americans used to have to do, and don't have to today. We have always used large numbers of immigrants in our labor force, the big difference today is that they can come here, work, send the money back home, and leave when they have made enough, or the work is done.
They used to say that the railroads were built on tea. Tea for the Irish immigrants who built the railroads from the east to the west, and tea for the Chinese who built the railroads from the west to the east. One big difference between then and now is that then, the immigrants stayed on in the USA, becoming citizens, raising their familires to be Americans, chasing the American dream, and often catching it. The people seen as a problem today are not immigrants coming here to live and work permanently, they are migrant workers. Migrant workers who don't assimilate into our general society. They don't need to. And because, as a group, they don't appear to try to assimilate, this breeds resentment among some here, while others go as far as they can to make things easier, so they don't need to assimilate.
Is it just because we are more understanding of others feelings today than we used to be, that we have a greater sympathy for the immigrants today than our forefathers did ? All the other non-English speaking immigrant groups were encouraged or even forced by our society to learn English in order to get along and to do business, but not those today speaking Spanish. All the ethnic groups had their neighborhoods, and their local businesses where their native languages were spoken as a matter of course, and still do even today, but only the Spanish speakers have made much of the US nearly bi-lingual. The western half of the US has gone farther on this route than the eastern half, but the influence is spreading there also.
While there is something to be said for helping people who don't speak English get along in the US, there is also a valid reason why people ought to learn the language of the country they live in, as much as they can, as well as they can, and as rapidly as they can. It's just the polite thing to do.
So, we have an immigrant (migrant/temporary/just visiting) workforce, many of whom do not speak English well, if at all, the feeling among large numbers of US citizens that they are "stealing jobs" and that their lack of English skills is deliberate rudeness, that even though they do work (and work hard) at the crappiest jobs for the lowest wages, many feel that they are taking advantage of our system, and being given preferential treatment and benefits denied to poor (usually white) Americans. No wonder it is such a touchy subject.