He hits the nail on the head- IMHO
"In the first place, we 
should insist that if the immigrant who comes here in good faith becomes 
an American and assimilates himself to us, he shall be treated on an exact 
equality with everyone else, for it is an outrage to discriminate against 
any such man because of creed, or birthplace, or origin. But this is predicated 
upon the person's becoming in every facet an American, and nothing but 
an American...There can be no divided allegiance here. Any man who says 
he is an American, but something else also, isn't an American at all. We 
have room for but one flag, the American flag... We have room for but one 
language here, and that is the English language... and we have room for 
but one sole loyalty and that is a loyalty to the American people." 
Theodore Roosevelt 1907