Rick emails to point out an analysis of the "outlier" poll that has shown Trump consistently ahead of Clinton. It uses a different methodology than the others, one that may control for the unique unknowns of this campaign better than the others.
Or not. We'll see. Personally, I think that all of the polls are worthless, for two reasons:
1. We've known for months that there is a significant Bradley Effect in play in this election cycle. When people think that their voting preferences will result in social consequences, they conceal their true choices from pollsters, throwing the polls off. We see massive social consequences for Trump supporters in many areas - being labeled "racist" or "deplorable", having signs stolen from yards, etc.
We don't know - and cannot know - how big this Bradley Effect will be. The Brexit campaign polls were off by almost 10% for exactly this reason. If the effect is that large here, we're looking at a Trumpslide. But the size of this is entirely unknown.
2. We don't know what voter turnout will be. We see lots of enthusiasm among Trump supporters, with Trump rallies being measured in the tens of thousands. We don't see that for Clinton. On the other hand, Clinton likely has a well oiled Get Out The Vote effort, one that the Republican Party seems to be trying to deny to Trump. How many Trump supporters turn out is unknown, and unknowable.
Both of these factors mean that the inputs to the polls (all the polls) are based on what's essentially conjecture. Since the inputs are garbage, the outputs are garbage. The numbers are worthless, because nobody knows the key factors that will determine the outcome.
But it's worse than this, actually. The polls are worse than useless because almost all of them are being used to shape the public's perceptions of who is winning. The pollsters - like the Media - are pushing one side; they've essentially weaponized the polls.
I plan to ignore all the polls because I simply don't trust the motivations of the pollsters, or the assumptions regarding respondent truthfulness or turnout.