I have a follow up question to the answers given in the US Election results 2016: What went wrong with prediction models? question. I suspect there is some violation of an independence assumption among the samples taken in election polling.
Specifically, I think that poll results affect the sample population. I think that people have gotten a sophistication of sorts with polls and deliberately try to skew their results by working in concert with others through social media. For instance, if you are a part of a demographic that is polled, it is likely that you or someone you know is also being polled. It would not be a stretch to think that this demographic is loosely networked through social media and therefore able to have an effect on one another.
My question is this: What sort of statistical test can one employ to test for the independence of the samples in the sample population?