I do not think a debate is appropriate at a social gathering, but sometimes I obliquely touch on a political subject just to test a person's character and intelligence.
True, but in some cases that's why people like Dershowitz get invited to dinners, because everybody there will be political junkies of one stripe or another, and it's expected there will be fights.
That used to be true in liberal circles 50 years ago, but today's "progressives" are only interested in associating with others who parrot the party line.
Progressives aren't the only people who give parties aimed at political discussions or other themes. I agree a party organized by a Party apparatchik would more boring than a Karl Marx lecture at a Harvard wine tasting, though, just a room full of mentally ill sexual deviants and ass kissing morons.