Hate to break it to you but the U.S. as an entity has pretty much always been racist and especially in the period Infinite portrays. There existed institutionalised racism that blurred (and indeed, blurs) class, gender and ethnicity that was and is made more obvious than in other Western countries by the huge and diverse contact the U.S. had with the Other. In that period, ideals and reality weren't so much opposed as blended together by fear, hatred, and in the best cases merely condescension.
If anything, it highlights the potential for corruption of those high ideals in a super-Americanised and racialised setting, at the beginning of the period wherein the U.S. began to take more of a leading global role, with ideology and perception shifting into place around it.
Take your pick of American literature and you'll see these themes and others like them recurring time and time again.