When a Mexican immigrates to the United States in search of a better life, he is not after the American dream, he is after the Mexican dream...because he is Mexican. There is only a small minority group of people left in this world that are searching for the American dream. The Americans, obviously... and there aren't as many as you might think. Because a few centuries ago, when the Europeans decided to immigrate to the western hemisphere respectively searching for their own European dream, they... well, they kind of killed them all and stole their lands.
It is almost impossible to accurately determine the exact number of native Americans that were sacrificed so Europeans can keep on "dreaming," but it is certainly in the 7-digit area and above. There is a term for that, it's called "mass genocide," but politicians prefer the term "colonization" cause it's more elegant. Everybody strives for a better life for themselves and their family, that's understandable, so I'm not judging the immigration to the American continent at all, every human being has the right, or should have the right, to move and settle wherever he desires. I'm judging the inexcusable attempt of pursuing your dreams in the expense of another human being. Native-Americans got wiped out cause the lands they were settled in had a huge vein of gold and oil which Europeans absolutely needed for their "dreams" to come true. And when you label this motivational concept as "American" when it has in fact led to the near extinction of the actual Americans, and subsequently to the demolition of all their own dreams and hopes for a better life... it's kind of an insult to them, don't you think? It's like referring to Hitler's attempt to carnage the entire Jewish community as "The Jewish Dream."
Dream on... by all means, have fun. Claim your right to life, liberty and the pursuit of happiness. But never forget... that when one group separates its own ambitions of well-being from the overall well-being of humanity... you only need to look at the 9/11 events to realize...
...that one's dream can be someone else's worst nightmare.