Looking back at the OP, I think there is one important thing to keep in mind.
There are some conservatives who would be perfectly willing to erect a 15’ wall along the border with Mexico and enact a shoot-to-kill policy. On the other hand, these same people feel that it is necessary to “keep the Middle East in our sphere of influence.”
As a Mexican, I generally think this is ridiculous. If they were truly concerned about immigration and not xenophobia, they would be interested in stabilizing the Mexican economy and helping it catch up to America as a place to live, not walling it off and using it as a vacation resort.
It is also important to keep in mind that this same viewpoint was taken about the various European immigrants over time, notably the Irish. It is nothing new, and no, it won’t cause society to collapse, though it will lower the percentage of Americans that are WASPs, and that is threatening to some people.
If anything, in my (rather personal) experience, Mexican-Americans specifically (and immigrants in general) are hard working, honest, and have a deep love for America and everything it means. Many of them volunteer for the military, for instance. Even in Spanish-speaking parts of towns (like the one I live in), the American flag flies proudly. In fact, many immigrants are rather conservative in their outlook, including my family. They like to view themselves as Americans first. My father certainly does.
A lot is made of the crime rate in Mexican-American communities. Well, frankly, this is the result of ghettos, more than anything inherent about Hispanics. If anyone cares to do some digging through history, Irish and German ghettos were much the same. The best thing to do is embrace them into society as much as possible, as is happening in Texas, New Mexico, Arizona, and Southern California specifically. I’m not as familiar with the situations in Miami and New York, though.
There was an article in a recent National Geographic about the rising Hispanic population, expanding into rural towns. They make note of the fact that sleepy, small towns of 2,000 have had 300-400% growth in Hispanic populations recently, and that has completely revitalized the towns, starting new businesses, bringing in new industry, and generally making life better. I think cases like these are important to take note of. These areas are embracing the new immigrants, and they are profitting from it.