Why does music and entertainment video work for the liberal messsage and not for conservative politics?

Rage, Blind, Bad Religion, even Matthews seem to appropriately have a cool message albeit liberal. I will be the first to say the conservative political music sucks maybe except for Creeds One being anti-affirmative action. Buts its mostly stupid, simple country music. I guess the ones for the troops are OK but they are still sappy and not deep.