One could argue the strategic mistakes of the Clinton campaign (ignoring the rust belt) and near fatal mistakes of the Biden campaign (which looks to be on issues swinging voters in battleground states) were driven by bad polling.
When I hear the conversation about "the polls were wrong" it's never been "the predictions were outside the error margin" so much as "voter sentiment was not accurately measured in regions where voters were most likely to flip and why they would do so."
When I hear the conversation about "the polls were wrong" it's never been "the predictions were outside the error margin" so much as "voter sentiment was not accurately measured in regions where voters were most likely to flip and why they would do so."