They try to estimate race , gender and age even for people they don ' t interview , obviously not terribly precise . They take the interviews they can get but realize that even in each locale they are unlikely to have a representative sample , so to fix this they ' adjust ' Lenski ' s word the data by weighting to match the election outcome . Their choices about which precincts to sample are a separate issue and it changes from election to election . But given that they only interview in English , primarily use white interviewers , and also are unwilling to send interviewers to precincts where they might feel uncomfortable i . e . Precincts are not randomly selected , even with a model that allows some key precincts to be sampled with certainty . So then to make the data look plausible because who would believe the exit polls if they produced a result that is dramatically different from the actual election outcome ? they have to weight the data to match the outcome and this has the effect of distorting demographics , particularly for minority groups , pretty badly . For example , look at the Latino vote this year , based on the exit polls Trump outperformed pretty dramatically when compared with the preelection polls , but the most valid preelection polls that included Latinos were also offered in Spanish , something the exit polls didn ' t do so there you are automatically looking at different populations and calling them the same . Now , I would actually be okay with all of the above if they would then release two weights with the raw data 1 the weight that they use for their own estimates , and 2 the base sampling weight without any election outcome adjustment . With this information we could see the extent to which they are or are not affected by potential biases . But they adamantly refuse to release those base sampling weights even to academics and that reaffirms my suspicion that their data are probably garbage . In terms of Trump supportersRepublicans , there is a decent amount of evidence that they don ' t participate in exit polls or any polls for that matter as readily as Democrats .