http://www.snopes.com/politics/immigration/newimmigrants.asp

It has been around for a couple of years and ... as with most such things ... presents an idealized (and hence distorted) view of the way things used to be ... and then proceeds to knock down the resulting "straw man" by presenting an correspondingly demonized (and just as distorted) view of the way things are today.

"Immigrants" (good & bad) have been coming here since the 1500's. I suspect that, as a group, the current crop isn't markedly different (better or worse) than those who have come before.

As for their willingness to fight for this country, illegal immigrants may not enter the US military. But, there are currently about 60,000 immigrants in the U.S. military, including 6000 US Marines. Roughly half of these 60,000 servicemen are NOT citizens, but are serving nevertheless.

There is no way of knowing how many members of the current US military are first generation children of immigrants, but I would guess that the number is substantial ... and that these people, just like those in WWII, give no thought to the country from which their parents came and are "defending the United States of America as one people". At least some of the men who have died serving in Iraq were first generation children of illegal immigrants.