I have to admit, Im not really sure what KMFDM or System of a Down are (my tastes run more toward Wagner and Verdi). However, I dont think its a leap in logic to assume that music which espouses extreme liberal viewpoints (I remember seeing some band chant Free Mumia at the end of their T.V. performance [Rage on the Machine???]) would appeal to people with a lefty bent and repel those with a Right-minded viewpoint.
Owl _ Eagle
Guns before butter.
The way that SoaD approaches politics is more along the lines of writing political essays for their website rather than trying to turn complex politics into catchy rhymes. And of course, they have a singer that doesn't sound like a crackling just hitting puberty teenage boy (RATM's now former vocalist... can't call him a singer.... Zach De La Rocha has one god awful voice!)