>Conventional (probability) polling rests on the assumption that a representative sample can allow estimation of the population
There’s nothing wrong with the math; the problem is that current polling, as this article shows, does not _get_ a representative sample! Current methods only get the people who own land lines; are near them when pollsters call (often mid-day); and are willing to endure the poll.
That’s on top of any polling bias wherein companies ‘adjust’ the results to match a prior turnout or defuse a result they’re not paid to obtain.
Remember Drudge’s online Polling all throuout the Primary?
Had TRUMP up big just exactly what he did in most States! =)