The Democratic primary process being so packed and crowded has made it very difficult for the public to delineate between candidates. All too often I run into people who have no idea who particular candidates even are and with the field being so full, polling has placed an increased importance on the reporting being done on the primary. Large political media outlets like the New York Times, Politico and FiveThirtyEight all release frequent updates on who’s winning the Democratic primary according to polls. This sort of contextualizing of the race has a huge effect on how its perceived by the general public.
Polls are theoretically representations of the population and allow us to peer into what the public thinks about a given set of candidates without committing the resources necessary to perform a comprehensive census of what every single person thinks. While I am not calling for us to begin making the implementation of censuses the norm, we must see that there are some effects associated with doing representative polls.
Studies show that public opinion polling can have the effect of further stifling the opinions of smaller minorities and can therefore make the voice of that group less represented in the given election than if they had voted purely based on the views individuals hold.
Also, even though these polls are engineered to represent the population as aptly as possible, they could be nearly exactly correct and there would be the candidates who argue that the polls are not the reality. Campaigns like the Sanders and Trump campaigns have a history of denying mainstream polling as mischaracterizing the country’s opinion, though it is notable that whenever these same campaigns are shown in an advantageous light they tout the polls as representative of their popularity.
This ability to cast doubt on polls is emblematic of the lack of trust that Americans have toward polling and what validity they have. Polls are built with margins of error and when there are numbers given to the probability that any given candidate will win an election, these margins of error are taken into account. Unfortunately, however, there is not much understanding of this and the reaction to unlikely election results (according to the polls) is that the polls are wrong. President Trump has literally said, "I believe in polls — only the ones that have us up … Other than that, they're the fake news polls." This, frankly, is propaganda and creates doubt in thorough and rigorous social science work that perhaps should be taken more seriously.
Polls are a scientifically proven way to keep up with the way the voters are perceiving the candidates in a given race, but there are some detriments to them fundamentally. These detriments can be overcome if we recognize them and ensure that they are taken into account.