This reflects a concern by serious polling operations that there is something fundamentally wrong with the conventional wisdom of polling. As the article notes, we are now in an era
When fewer people are reachable or willing to talk to pollsters.Polling has been decreasingly accurate in recent elections. The extent to which this inacccuracy reflects "tribal" voting - surges of non-whites showing up to vote for a non-white presidential candidate - is also unclear. Perhaps the 2016 voting cycle will be more predictable; apparently Gallup wasn't sufficiently convinced to proceed.