And yet the mainstream polling firms will continue to sample Democrats with a 5-7% advantage so that they can claim that Trump is unpopular, deserves removal from office, is leading country in the wrong direction, etc.
I think they came up with this weighting after Obama’s immaculation and have never strayed from it since.
Don't you expect pollsters to do their job? If they're paid to support a certain narrative, a lot of them will work hard to deliver what they have promised. [One of my professional standards was that I would only present the truth to the best of my ability. I was very good at that, and my clients knew that I was only providing facts - back in the days before the response rate dropped so far that it's hard to know what the truth might be.]