The Accuracy of Polls

Is The Polling Industry In Stasis Or In Crisis? (Nate Silver) from FiveThirtyEight
"We have seen no widespread decline in the accuracy of election polls, at least not yet. Despite their challenges, the polls have reflected the outcome of recent presidential, Senate and gubernatorial general elections reasonably well. If anything, the accuracy of election polls has continued to improve."
This article showcases the growing list of problems the polling industry faces in getting accurate polls.  One can easily see some polling groups (and maybe most) getting wildly off-the-mark results based on what Silver says here.