that YouGov massive release of data from two dozen states. However, and this is worth noting, these are not traditional polls. They are "callbacks" of people who were surveyed online last month. As such, they are useful to look at how those folks have shifted their preferences since September, but the caveat that these are not unique samples should be remembered.
I conclude that the people at YouGov don't read my blogs and missed my criticism of CNN/ORC panel polls on debates. That's not the way it should be done, or rather, the headline result of the second wave is not worth reporting. Repeat interviews are very useful. The point is to see how people have changed their minds and not to mistake fluctuations in sampling error as changes of opinion. An unavoidable problem is that having stated an opinion in the past may affect what people say (maybe they don't want to seem to be flip floppers or oppositely maybe they want to prove they are open minded and react to new evidence).
But there is no way no way that the second wave of a panel is going to be a representative sample. Not gonna happen.
Trying to undo the damage by weighting would work if all White women age 25 to 40 with college degrees were exactly identical with the same opinions about everything. They aren/t I've checked (the only almost universal opinion is "no thank you, I would not like to engage in sexual intercourse with Robert Waldmann" (actually I really haven't asked that question of a large enough sample for reliable statistical inference (I am very shy in real life))).