Dear colleages, I think I'm getting to this discussion a little late, but here goes: I was reading a discussion about whether voting results represents a voluntary response sample, since the voters are people who care enough to vote. But doesn't this designation rest on a question of definitions? What is the population of interest here? All adults of voting age? All registered voters? All 'likely' voters (whoever they are. The media seems to know)? Only the actual voters' opinion about who is President really matters (polls don't count), so maybe *they* are the population of interest. So the vote is not a sample, but actually represents a census of those opinions that matter. Just a thought.