I was perusing the thread and saw your comment. I cannot find the data at my fingertips, but I believe this is no longer true.(if you consider 1st and second generation)
If you use birth in the USA as a defining parameter (which Mrs. Bush was not), then it would be true.(barely)
I was using Webster's definition of immigrant which is as follows:
im·mi·grant: one that immigrates : as a : a person who comes to a country to take up permanent residence
Under this definition, most of us in the USA are not immigrants....and not just 'barely'. Over 90% of us are not immigrants under Webster's definition.
Senor and Senora Bush and other immigration cheerleaders who constantly tell the blatant lie "we are all immigrants" or "we are a nation of immigrants" have corrupted the meaning of the word in order to push their poltically correct agenda which has already Balkanized Houston and Los Angeles and is heading north very rapidly.