Even if polling had been exactly right, you wouldn't have been that confident in the outcome.
In my unsophisticated toy model, plugging in the exact actual result as the polling average (but not telling it how the actual vote went) spits out 66% R-34% D. Clearly one side favored, but hardly a guarantee. Because the result was close, and even highly accurate data in a close result yields an uncertain forecast.
Remember that asteroid a month ago? We knew what its position would be seven years in the future with a precision of a few hours. But because the position was very close to an impact, even that high precision was not enough to rule out an impact.
In my unsophisticated toy model, plugging in the exact actual result as the polling average (but not telling it how the actual vote went) spits out 66% R-34% D. Clearly one side favored, but hardly a guarantee. Because the result was close, and even highly accurate data in a close result yields an uncertain forecast.
Remember that asteroid a month ago? We knew what its position would be seven years in the future with a precision of a few hours. But because the position was very close to an impact, even that high precision was not enough to rule out an impact.