What is this "representative sample" that you're talking about?
It is well-known that the subset of the population that goes to the polls is NOT representative of the country as a whole. That is why pollsters are so careful to get polls of "likely voters". Because Republicans tend to be more motivated to vote than Democrats, so if they just took a poll of everyone they called, the results would always be strongly skewed Democrat.
(Getting this right is very tricky, and different methodologies around it is one reason that different pollsters often have a consistent difference in the polls that they produce.)
It is well-known that the subset of the population that goes to the polls is NOT representative of the country as a whole. That is why pollsters are so careful to get polls of "likely voters". Because Republicans tend to be more motivated to vote than Democrats, so if they just took a poll of everyone they called, the results would always be strongly skewed Democrat.
(Getting this right is very tricky, and different methodologies around it is one reason that different pollsters often have a consistent difference in the polls that they produce.)