Calvin Coolidge (a favorite of Ronald Reagan and mine) was on target on December 6, 1923 when he addressed Congress with these words -- as relevant today (if not even more) than it was then:
"American institutions rest solely on good citizenship. They were created by people who had a background of self-government. New arrivals should be limited to our capacity to absorb them into the ranks of good citizenship. America must be kept American. For this purpose it is necessary to continue a policy of restricted immigration. It would be well to make such immigration of a selective nature with some inspection at the source, and based either on a prior census or upon the record of naturalization. Either method would insure the admission of those with the largest capacity and best intention of becoming citizens. Those who do not want to be partakers of the American spirit ought not to settle in America.”
I've said it before and I'll say it again, mere documentation alone doesn't imply assimilation.
Excellent quote by an often-underrated conservative President.
I will say one thing. In the early part of the 20th century, many people thought that the Jews, Italians, and Irish who were coming over in droves were unable to assimilate, that they were dirty, criminal, and incapable of embracing American culture. That was, of course, proven untrue.
Will Hispanics follow the same route? I think this depends largely on what we do. For many Hispanics, yes, I think they do, and will, but others do not.