That's true and I certainly understand where you are coming from (and I appreciate your response). I know it wasn't George Bush who made the sole decision to go to war. However, it was George Bush that lied to the public, his people, the people who voted him into power, about WMDs (“The Iraq regime continues to possess and conceal some of the most lethal weapons ever devised.”) and he allowed the interrogation (torture) of detainees.
There was a reason there was a "fuck bush" mentality. Justice didn't assume the crowd hated bush because they were hip hop fans, he assumed they hated bush because bush was a terrible president who lied and started a pointless war, amongst other things.
I'm not claiming it was a reference to the war specifically. I'm just providing examples of why George Bush was mentioned, as opposed to any other politician like Sarah Palin or Glen Beck like Amadeo suggested. I am aware this was '05 and those specific politicians weren't necessarily around, but you see the point I'm making.