Do pollsters present the actual numbers observed?
Virtually never. All pollsters have a demographic model of the population and want their sample to conform to it. With only 500 people in a poll, there might not be enough single young black Republican women or too many married older white Democratic men. Statistical techniques are used to correct for these deficiencies. Some parameters, such as the fraction of voters in a state who are women are well known and not controversial. However, normalizing for political affiliation is very controversial. If a pollster decides that, say, 60% of the voters in some state are Republicans and 40% are Democrats, then even if a poll says the Democrat and Republican are tied at 500 votes each in the sample, he will count the 500 Republicans sampled as 600 and the 500 Democrats sampled as 400 and conclude the Republican is ahead, contradicting the raw data. Some pollsters determine the party affiliations based on the exit polls of the previous election, and some use long running means of their own po
