What instantly kills the vibe at a party?

Talking about serious political stuff - the Gulf War, Stormin 'Norman, the US coup last week in Latin America, the WMDs lie, the unlivable, unsustainable suburbs, the transit problem in US cities, falling purchasing power, privatized housing, falling lifespan and poor US educational performance.
The hippies don't want serious to interrupt the fake fun on the weekend, or the werkkk they do all week for NATO!