Patrick Ruffini and Kristen Soltis Anderson wrote an op-ed  on how to reform polling after a disastrous 2016 presidential campaign cycle:
We also may need to look beyond polls alone for answers. Just as you shouldn’t fly a plane until multiple systems are checked and rechecked, we shouldn’t rely on polls alone to tell us how we’re doing. Indeed, there were signs this year that the Democrats’ electoral map was more fragile than the polls made it appear to be.
While the polls gave conflicting signals about the state of play in the upper Midwest — showing Iowa and Ohio leaning toward Trump, and Michigan and Wisconsin toward Clinton — demographically, these states are not very different, each having a comparatively high share of white voters without college degrees. Demographic modeling  by the likes of David Wasserman of the Cook Political Report provided a more accurate view, showing the Rust Belt poised to move solidly toward Trump. Nationally, our own demographic model , relying on factors such as the percentage of white voters without college degrees, outperformed state polling averages in anticipating which states Trump had a chance of flipping on his way to an electoral college upset.