Primary polling outside of exit polls is nonsense. How are you going to collect unbiased sample when Trump voters are some of the loudest and most obnoxious people on the planet? You can’t put a filter on their enthusiasm because it’s consistently and directly correlated with their voting habits. So how do you control for enthusiasm bias in getting respondent participation while targeting the information the enthusiasm is related to?

You don’t. You can’t. You ignore it and publish bullshit.