Well there is their public belief and private belief. The public belief is fake confidence to try and depress Trump voters. The private belief is that they are scared as hell. You can tell as we get closer to election day, libs get angry, nasty, and unreasonable.
We have a forty year history of polling. Or more. Can ANY of us remember, ever, a poll being wrong in the OTHER direction? Even one?
Even a college dropout who failed one semester of statistics knows that THERE IS ABSOLUTULEY NO RANDOMNESS HERE. Every one of these polls is essentially the WICKED WITCH looking into her mirror trying to decide just how pretty she wants to be today.