The pollsters missed out on the invisible Trump voters in the battleground states. I haven’t seen any evidence that they’ve learned their lesson. Nate Silver at least gives him 28% chance of winning with tipping states being Arizona, Florida and Minnesota.
I'm currently aging polls after two months, since the rate of polling varies. Repolls by the same polling group replace their prior polls, but older polls will decrease in weight and eventually drop off.
Next month, I'll probably drop polls older than one month, if polling by the top firms becomes weekly.
-PJ