Some polls in Iowa were so wrong, they were giving Trump an advantage of 10-15 percentage points?
How can they be so off?
Polling…The standard for the last several decades for scientific polling was the telephone…the home telephone.
You could tell where the respondents lived and therefore figure out the sampling and make sure it was reflecting the population.
But now, with cell phones it is harder to make a scientific sampling…You can’t tell where they live from the telephone numbers…and people get really angry if you call them on their cell phones and ask, “Who are you voting for?”…not to mention all the associated questions a poll taker has to ask to do it right.