So far, four five six pollsters have released national surveys using samples taken after the end of the Democratic National Convention, and have data from the post-RNC period. The median swing is a 7.0 ± 1.1 2.0 2.1 % (± estimated SEM) move toward Hillary Clinton.

Here are this year’s bounces, added to the previous graph.



Individual polls:

Pollster Pre-DNC Post-DNC Swing toward… Raba Clinton +5% Clinton +15% Clinton 10% PPP* Clinton +4% Clinton +5% Clinton 1% Morning Consult Trump +4% Clinton +3% Clinton 7% CBS Tied Clinton +7% Clinton 7% CNN Trump +3% Clinton +9% Clinton 12% YouGov (4-way) Clinton +2% Clinton +5% Clinton 3%

The Pre-DNC measurement from PPP was taken in June, predating both conventions. The resulting swing therefore represents a combination of the Republican and Democratic conventions. However, since the median post-Republican convention swing was only 1 point, it was still informative and I included it. Since you can do medians in your head, you can see that this does not make a difference given the current data set.

YouGov leads its report with the 4-way (Clinton v. Trump v. Johnson v. Stein) result, showing a 3-point swing toward Clinton. The 2-way result shows a 2-point swing in the opposite direction, toward Trump. Again, the median is the same no matter which one of these is used. However, the error bar is affected slightly.

I have seen some sniffy comments in the news that Hillary Clinton’s post-convention bounce is smaller than Bill Clinton’s bounce in 1992. However, by current standards, Hillary Clinton’s bounce is large. As I wrote the other day, post-convention bounces have been small for presidential elections since 1996, which I suggest is a symptom of political polarization: voters get entrenched in their support.