I think maybe since there isn`t a great deal of access to the mainstream media and people don`t understand the language of mainstream media, if you put music out there with lyrics that are loosely political, people absorb some of it and spit it back out.
I grew up under Thatcher. I grew up believing that I was fundamentally powerless. Then gradually over the years it occurred to me that this was actually a very convenient myth for the state.
I don`t see it in terms of changing things, but rather using language and music as weapons for fighting a mainstream media which is predominately right wing, and loyal to the political framework and its corporate interests.
Generally speaking, if people are prepared to stick their heads above the power pit, like Zinn says, and absorb what`s going on around them, it makes them think.