OK, just this once more then I'll let you have the last word.
The Economic benefit to those communities is felt because Wal-Mart charges less for the same product, leaving each consumer with more money to spend on other items. If Wal-Mart was no cheaper, then they would not be able to run all those other businesses out of town. (I'm sure you can site specific examples of pricing discrepancies, so I'll confess up front that I'm talking in general terms about any business which dominates a small retail market like that.)
You seem to be continually falling back on that socialist argument that there is a fixed amount of "wealth" in a community, and the only thing subject to debate is how the existing "wealth" is proportioned. To refer to your last example, "Opening a Burger King across the street from the town McDonalds does not prosperity make" I'd like to see you tell that to the formerly unemployed workers at Burger King, or the salesman responsible for selling ground beef in that territory, or the garbage collectors, or for that matter, the guy who can only afford to take his kids out for fast food when the chains run a special. His economic benefit isn't direct, it's felt in greater choice for him and his family. Just because there are fewer businesses doesn't mean there is less business.
You've been polite, and I'd like to be the same, but I have to admit that your mention of (admittedly recently) outdated economic theory is just a way for you to try to lend credibility to the fact that you feel threatened by immigrants. Like it or not, anyone who manages to prosper personally, adds to the overall wealth of a community. And in my experience, most immigrants are the kinds of people (personally I mean) who will go the extra mile, leave their freinds and family, and work harder than average, often in the most difficult of conditions, in order to prosper. Not only is this the kind of person I want in my community, I want them running my local market, and my local wal-mart, and I don't care what color they are, or what language they speak in their home. If they'll step up and take responsibilty for themselves, then they can come from the worst, third world backwater imaginable, and I'll welcome them as my neighbor.
Also, I think you really should read "The Economics and Politics of Race" by Thomas Sowell. It's a short book, and a good read, written by one of the great thinkers of our time, where he painstakingly cites the specific economic data to refute all of your "fixed wealth & redistribution" claims. You seem a bright person who would no doubt benifit from, and make good use of, the increased knowledge.
And now I have to get some work done.