The stories given by OP don't seem to support her point as much, it seems to me. The fact is that she and 'other who don't belong' where in those parties. Contrast this with some crusty societies of Europe, such as Germany or the UK. You are simply not going to get invited or even be remotely exposed to those circles. Moving to the UK I was shocked by how openly classist they are. And unlike the US, where at least you can hope to climb the class ladder with money, it's almost impossible to make it there. The phrase 'old boys club' is both figurative and literal.