For those with sincere interest in the sampling issue, I would recommend Mark Blumenthal’s post from September 23, 2004: Weighting by Party.
This post is useful because it address issues under discussion today, but may perhaps be more persuasive for some because a) it was written eight years ago, and therefore lacks the political context of contemporary discussions, and b) it is about a situation in which some Democrats were complaining that the polls were over-sampling Republicans.
