To these people, America is a unrealistic abstraction, which can be a bountiful land of promise or a land of imperialist brutes. Depending on the situation, they take the one and ignore the other. America can be a pretty convenient thing. In short, they are examples of the effectiveness of public school and media brainwashing.
"But [making a show of ] stupidity is not enough. On the contrary, orthodoxy in the full sense demands a control over one's own mental processes as complete as that of a contortionist over his body. ...Society rests ultimately on the belief that [leadership] is omnipotent and that the Party is infallible. But since in reality [leadership] is not omnipotent and the Party is not infallible, there is a need for an unwearying, moment-to-moment flexibility in the treatment of facts." "The key word here is blackwhite. ...Applied to an opponent, it means the habit of impudently claiming that black is white, in contradiction to the plain facts. Applied to a Party [agent, vassal, or unwitting gamesman], it means a loyal willingness to say that black is white when Party discipline demands this. But it means also the ability to believe that black is white, and more, to know that black is white, and to forget that one has ever believed the contrary...." - from 1984 by George Orwell