Every election brings a raft of complaints about polls. I don’t expect this one to be any different — Republicans will bemoan the overabundance of Democrats in the samples, while Democrats will claim that the polls under-sample minorities.
What make these criticisms more salient this year, however, are signs that “working the refs” is having an effect on polling companies. In 2008, in response to complaints from many observers that minority and young voters were undercounted, Gallup actually produced two models: “traditional” and “expanded.”
Read more at Real Clear Politics.