I really don't have to travel anywhere, I have a multicultural extended family, so I wouldn't know about not socializing with others. We have two buildings down, the Pentagon attacked, over three thousand dead, antrax here and there, not everyone is here to build, I would like that acknowledged.
It used to be that immigrants came here with no plans of ever leaving, root hog or die, they were in it for the long haul and it was vitally important to them that America succeed That is not the case anymore and I rightly feel, as a native american, that a far, far, better immigration plan should be in place.
For a nation of native born that did not slam the door in other people's faces like we could have, and that has poured trillions, that would be trillions towards the benefit of the poor and huddled masses world wide, they are still poor and huddled and hate our guts if we are not there to fight their fights, blow their noses, educate them, medicate them, bring the food and cook dinner, do the laundry, and give them advise on their love lives. Others hate us enough to come kill us out of pure green envy. We can no longer afford open borders and an insane immigration policy period.
Your concern about immigration policy is reasonable. At this point 1 million legal and 1 million illegal immigrants come to the U.S. I personally fel this is too much. Ideally I would set the level at 250,000 legal immigrants (all skill-based) and no illegals. This won't happen though. Many immigrants do plan to stay in America for their entire lives, some do not. Remember also that unlike the "old days" modern transportation has made coming and going anywhere in the world an easy proposition. The immigrants aslo want to see America succeed, if America fails, they fail also or have to go back to their country of origin. Your claim that the terrorist attack occured because of envy of the U.S. is untrue. The attack occured because of U.S. foreign policies (Basically, support of Israel, Support of certain regimes in Middle East, etc.). Nobody is going to say, "Gee, those Americans have two cars in each house, color televisions, and running water. Let's go get 'em!" Life is a little more complex than that.