Don’t get hung up on the internals, you worry warts. Check the Gallup poll today. Check other polls. All of ‘em “scientific”. All of them garbage. Call 1024 people yourself and conduct a poll, it’ll be as valid as any of them. ANY!
The problem is you have to call well over 9,000 people to get 1,000 ~ then caller ID negates the randomness of the calls ~ a small special interest group like homosexuals (GBLT) can pledge to ALWAYS answer pollster calls and they will end up appearing to be 10X their actual number!