I, too, despair that the cultural/ethnic battle already _has been_ lost, at least for some portions of the country.
Other, small, isolated portions may be able to retain their "traditional" (read: white European) American culture and ethnicity. What will probably save these locales is their relative UNattractiveness to the alien hordes that are currently invading our nation.
Could the current trends be reversed? Yes. But they will not be. The political "costs" of doing so are too radical, too draconian.
For, the only way to truly reverse the damage being caused by illegals is to forcibly IDENTIFY, BRAND, and EXPEL them.
Now isn't that line (which we have heard before) a bit too hard for most of the dear readers of this forum to swallow?
I didn't think you were ready to do that.
And this is exactly why we are doomed.