One lesson of the 1990 elections was that politicians would rather not talk about politics -- taking sides on issues can be too risky. Mainstream popular culture prefers to stay on the sidelines, too, since there's no use in alienating a potential fan. When pop singers get earnest, the message is likely to be about compassion and charity rather than anger, resistance or placing blame.
The only militant messages headed for the pop charts appear in rap songs: a new contingent of self-described "radical" rappers are determined to carry serious ideas onto tape decks and dance floors. Three years ago, Public Enemy was the only rap group taking a combative stance on issues; now, half a dozen bands have followed up, while established groups make at least token efforts to be "righteous."