On average, his poll numbers in a state haven’t moved from two weeks before the rally to two weeks after. His poll numbers in any state relative to national polling (a metric used to eliminate the drag on his state numbers from national changes) have improved 0.1 percentage points on average. There are times when his poll numbers have surged after a rally. In the two weeks after his rally in Pennsylvania on Aug. 20, for example, his poll numbers in the state shot up two points. If we assume the same turnout from non-White voters, Biden doesn’t actually see a decline in support relative to Clinton.

Source: Washington Post October 12, 2020 20:27 UTC