I have had, in my teaching career over 8000 different students; I have taught ESL, and I have taught subject matter courses for English Language learners, as well as for kids born and raised in the US. What I have seen is that, regardless of ancestry, those who grow up here or in Western Europe are more likely to take it for granted that prosperity without toil is normal, and that the government or someone else is responsible for whether or not their needs are met. US natives are more likely to slack off, coast, and choose low personal standards.
On the other hand, Immigrants from the developing world, (from nations with oppressive governments, shattered economies, primitive infrastructures, etc.) recognize that this nation's prosperity is both an opportunity and a sacred trust. They work harder, set higher personal standards, and depend on the government less.
All of the people who worked on my home remodel in San Diego were immigrants. They worked harder, more cheerfully, and did a better job than the US natives who worked on my homes in Texas and South Carolina. (The immigrants would have worked more cheaply, too, but I give merit pay bonuses.)
The problem is that life in the US is pretty easy, and that makes a large percentage of our kids soft and lazy. We NEED the influx of people who are shaped by hard places to balance out that softness. Otherwise we would be the land of the entitled and the home of the complacent.
I believe everyone will soon understand the importance of immigration. Not only does immigration provide jobs to many people but also has many more benefits. In a world with an aging population we are soon going to see more and more people required to do certain jobs and whose going to do this, you guessed it immigrants.
It provides jobs for those that are disappointed with their lives in their own country and allows them to accomplish their dreams of doing whatever they want to in life. (actor, writer, scientist, etc.) On top of that, were giving life, liberty, and the pursuit of happiness in a democracy for those who have few or none of these things, just like The Declaration Of Independence promised. Even if they didn't want those things, they aren't forced to go to America, so it's a free, optional ,and fair choice.
Immigrants are good if they accomplish as a whole 3 things:
1) There is a very small minority of them
2) Their fertility rate is ALWAYS lower than that of the countries ethnic group, so they never become the majority
3) They fully integrate
If they don't accomplish these parameters then they become a large problem, especially if they believe in different religions.