If you look at the Trafalgar Group polls, they always use a large base for their analysis ....their polls usually have 1,000 or more respondents...compare that to other polls that run 4-500 respondents and you can see why they are successful.
It’s much easier to run a scam poll when you have smaller numbers....15-20 over sample of one group can make the poll say whatever you want.
In a poll of 400 people, an oversample of 20 people swings the poll 5%.