The convention season is arguably the most crucial period for the presidential election. Historically, it’s one of the very few points in the contest in which polls tend to dramatically shift in a way that proves durable. Whichever candidate comes out on top when the dust settles is more likely to actually win in November.
So far — though it’s still early — things look like they went very well indeed for Hillary Clinton. The question is whether it will stay that way.
- A Fox News poll found Clinton ahead of Trump by 10 points, up from a 6-point lead in late June.
- A Gallup poll found that the public’s reception of the GOP convention was sharply negative, whereas feelings were more mixed about the Democratic convention. According to the poll, Trump’s speech was the least well-received of any major party nominee going back to at least 1996, and the Republican convention was the only one held since 1984 that drove away voters rather than attracting them.
- A CNN national poll finds Clinton ahead by 9 points — way, way up from a 3-point Trump lead after the GOP convention.
- A CBS national poll now finds Clinton ahead by 7 points. After the Republican convention, CBS had found that Clinton and Trump were tied.
- A Morning Consult national poll now finds Clinton ahead by 3 points. After the GOP convention, Morning Consult had Trump ahead by 4.
- Public Policy Polling now has Clinton ahead by 5 points. The outlet didn’t poll after the Republican convention, but their most recent national poll, from a month ago, found Clinton ahead by 4.
- CBS’s Battleground Tracker, which repeatedly surveys the same voters from 11 swing states, found that Clinton now leads Trump by 2 points among its panel, compared with a 1-point Trump lead after the GOP convention.
The convention period is really, really important
Political scientists Robert Erikson and Christopher Wlezien have found that polls during and immediately after the convention period are indeed quite volatile. But once that volatility dies down, one party usually emerges from the convention chaos with a durable lead.
"Although the convention season is the time for multiple bounces in the polls, one party ends up with an advantage when the dust clears. And this gain is a net convention bump rather than a bounce," they write in their book The Timeline of Presidential Elections.
In other words, whoever comes out on top after the convention period usually stays on top. Indeed, the authors looked at general election contests going back to 1952, and found that the candidate who was in the lead two weeks after the conventions ended went on to win the popular vote every single time.
Now, it would be a mistake to treat this as an iron law. Some of those races ended up being quite close and could have conceivably tipped the other way — and Al Gore lost the presidency despite winning the popular vote.
Still, the authors’ research shows that conventions tend to have a consistent and profoundly important impact of the type that’s hardly ever observed at any other brief phase of the campaign.
"Once the conventions are over, further campaign events — even presidential debates— rarely result in dramatic change," they write.
But we should check back next week to get a better idea of whether Clinton truly did benefit
Right now, though, we’re still in that volatile polling period when we’re waiting for the dust to settle.
And it remains to be seen whether this bounce will prove to be temporary or permanent for Clinton.
Trump got a bit of a bounce after his convention too, after all, and these early polls seem to indicate that it’s vanished.
Plus, as Jeff Stein writes, there’s this weird phenomenon where partisans are more likely to actually answer polls in the wake of their own party’s convention.
And it should be noted that even most of those new polls where Clinton does well still tend to show a close race.
Still, it’s of course better for Clinton to get good news after her convention than bad news. So the early signs for her campaign are encouraging.