Modeling correlated polling errors is basically what 538's models are all about. They model how far off the polls could end up being from the actual result based on past elections.
The polls are never 100% accurate. The pollsters have to estimate how many of each type of voter will actually show up to vote and what the response rate for each type of voter was. It is not an exact science.
The polls are never 100% accurate. The pollsters have to estimate how many of each type of voter will actually show up to vote and what the response rate for each type of voter was. It is not an exact science.