I guess there were many factors contributing to that. One of them is linguistic. Anything that sounds in English is likely to be wider known (and thus to become more popular) than anything that sounds in any other language. E.g., when a Hungarian band Omega made their Gyöngyhajú lány thing in 1961, few became aware. It took the Scorpions to make their White Dove out of it for it to become a hit. Anyway, Rage Against the Machine are an American band, aren't they? So, they're from the non-red part of the world whatever their political views may be, right?