I also just reject the notion that most presidential polls used samples of 1,500 - to take an example from about a month before the presidential election (as things ramp up in the final month, which is also the same for the UK), you have a CBS/NYT poll for October 27th-29th with a sample of 600, a TTIP with a sample of 900, an Ipsos with a sample of 800. Even the polls with big sample sizes (there's a few with 2000) are misleading because UK polls are conducted daily, while US polls gather their sample data over multiple days, so on average about 500 per day get sampled, often less, compared to 1000 per day in the UK. Before the final fortnight of the US presidential election 2012, I couldn't find a single example of a company polling a 1,000-size sample in a single day. All polls using 1,000+ sample sizes were spread over *at least* 3 days.