The history of convention bounces
Bottom Line: With the DNC now behind us and the RNC underway today, I wanted to take a look at what’s generally gained by political conventions. Four nights of primetime coverage with your biggest names and theoretically best foot being put forward naturally has a generally positive effect on public perception. This isn’t mutually exclusive, both parties have historically benefited similarly from conventions. The most comprehensive research on political convention bounces was conducted in 2008 by Gallup. Here’s what they found:
- All but two political conventions led to bounces in polling averages afterward
- Both of the conventions which didn’t lead to a bounce were led by Democrats challenging an incumbent Republican President (who lost their elections)
Those two conventions – George McGovern’s in 1972 – which led to flat polling afterward & the 2004 DNC when John Kerry was the party’s nominee. He actually lost a point of support following the DNC. The only candidate with which that has happened in the polling age. All in the average bounce has been:
- +5.2% by Democrats
- +5.3% by Republicans
In other words, Republicans have historically gained an ever so slight edge on Democrats after conventions but typically the advantage one party nets washes out with the other party’s convention. The first pollster with complete results taken the week before the convention and during the convention was CBS/YouGov which showed Biden with a ten-point advantage over Trump nationally in both polls – hence no bounce. That’s something I’ll be watching as this week unfolds. History doesn’t bode well for Joe Biden, as a Democrat challenger to an incumbent Republican President – if he didn’t net a bounce. To be continued...