Huh? The first European colonists here came from monarchies and the remnants of old feudalistic cultures. How did they manage to form a liberal constitutional republic? If those immigrants were bound by the political structure of their countries of origin why should Mexican immigrants and their descendants by guided by the same?
Shared culture and heritage and a love of ideas from the European Enlightenment philosphers along with a tradition of old English common law that began even before Magna Carta and which by the death of Charles II had pretty much neutered the Brit monarchy. Mexico lacks that tradition and their citizens swarming here en masse lack that commonality with this nations founders who did the wonderful things you admire.
So, you think turning a Euro-descended nation into an "other"-descended nation is all hunky dory? even in light of hyphenated Americans? If so, why? Do you have something against Caucasians?
BTW...great bean.