“What happened in 2012?”
I, like many other Republicans, including Rush Limbaugh, came to believe the external polls were seriously wrong and that Romney really was going to win. Example: http://www.breitbart.com/big-government/2012/11/01/eight-reasons-pro-obama-polls-are-wrong/
Romney’s internal polls were wrong too (in the other direction): https://newrepublic.com/article/110597/exclusive-the-polls-made-mitt-romney-think-hed-win
Now, in this election, I don’t know what to believe about any of these polls. One national poll says Hillary is up by 10 pts. Am I supposed to believe that? I didn’t believe Obama was ahead in 2012 and he was.
Who knows for sure? Apparently the LA Times Poll that has Trump up by 4 was accurate in 2012 calling the election for Obama, with close to the predicted margin of victory.
For this particular poll, one thing that confuses me about their methodology is that they used random calling based on computer generated random numbers. Those that answered got polled, but how did they come up with the specific percentages of Democrats, Republicans and Independents? Is this the split that ‘just happened’ on the basis of random calling, or did they adjust after they collected the data? Plus, if its random calling by a number generator, how did they know if the voters were registered? The only way I could see this being done is by sequential questions, the first of which would be ‘are you registered to vote?’. Then they must have asked party affiliation, but this doesn't take into account leaners, etc. I'm not a statistician, but it seems to be that random number generated calling, nationwide, of only ~892 people, would lead to marked variability in results.
I can tell you one thing that weighs heavily in Trump’s favor. He has shattered the record for small donations under $200. No candidate has raised as much money from the little guy as Trump has. Those people will be voting. I don’t remember the number, but it was impressive, and if you look around on FR in the last day or two, you can find the article about it. That along with his rally turnout gives me hope that these polls are out there to frighten us away from voting for him.