It seems like what got the "felling the biggest tree" thread derailed was a comment about Mexicans, with the assumption being that they're all "bad" (whatever that means.) I think what was probably meant to be said was that ILLEGAL immigration is a really big problem. Not so much any specific ethnic group, but just the plain fact that way too many people are entering this country illegally.
I see nothing wrong with establishing a gauntlet at the borders, north and south, putting a total stop to illegal immigration. Let's return to the days of my great grandparents whereby you need a sponsor family in this country who will be responsible for you. They will make sure there's a job for you, that your papers are in order, that you're able to speak english prior to entering the country, that you have health care coverage, etc.
Someone said this country is a great melting pot. Well, it probably used to be, but now it's more of a mosaic. It seems most new immigrants want the benefits of living in America without actually becoming an American (speaking english, paying taxes, obeying the law, etc.).