vision 2020

Will Biden — or Trump — Get a Post-Convention Bounce?

Are conventions changing the presidential horse race? Photo: Alan Crowhurst/Getty Images

At the end of last week’s Democratic National Convention, a lot of Democrats were understandably excited about the event’s possible impact on the presidential race. It was a generally well-executed event with some memorable moments and images, a good mix of positive and negative messaging, and a strong performance at the very end by nominee Joe Biden. Might not Biden get a convention “bounce” that could expand his lead over Donald Trump to something almost insurmountable?

There have only been two national polls released since the DNC ended, and neither shows any Biden Bounce at all, as Politico reports:

[T]he latest Morning Consult tracking poll shows Biden 10 points ahead of Trump, 52 percent to 42 percent. That is statistically unchanged from an 8-point lead on the eve of the Democratic convention, 51 percent to 43 percent….

CBS News/YouGov panel-back survey, in which respondents were surveyed before the convention and then reinterviewed afterward, also gave Biden a 10-point lead — unchanged from before the convention.

So the good news for Biden in these polls (neither of them, it should be noted, gold-standard live-interview polls) is that he’s still kicking Trump’s butt. The bad news is that his lead does not appear to have grown, despite the best efforts of those participating in the DNC.

Now it’s possible, of course, that absent any DNC, the race might have narrowed over the last week, and the convention kept that from happening. We may never know. Yes, we could get more polling data at any moment. But now that the RNC is underway, it’s harder to sort out the bounce from a possible counter-bounce. And it’s unclear how much of a bounce in either direction we should expect even with the infallible measurement we lack. As Geoffrey Skelley noted last month, the phenomenon has steadily declined in significance in recent presidential cycles — notably since 2000, when George W. Bush and Al Gore each got an eight-point post-convention polling bounce:

[C]onvention bounces have been getting smaller, which is likely a byproduct of how polarized our politics have become. There are just fewer swing voters, so it’s harder for a candidate to attract support outside of his or her core base of supporters.

In 2016, Trump’s convention bounce was three points, and Hillary Clinton’s was two points. Had they been pushed together like this year’s events, the net effect might have been negligible. And it’s not completely clear this year’s virtual events are going to penetrate public consciousness (TV ratings are down, but online participation is up) to the extent we expected from old-school conventions.

That doesn’t mean you should just ignore the post-convention polling that is slowly rolling out. As David Byler explained last week, conventions can produce important findings more nuanced than the top-line horse-race numbers:

The most important question the post-convention polling can answer: Is there a Harris effect? Biden officially announced that Sen. Kamala D. Harris (Calif.) would be his running mate only days before the convention, and most Americans haven’t spent much time listening to her speeches or researching her policy positions. On Wednesday, Harris introduced herself to many voters for the first time — and their response will tell us if she’s exciting the base, driving moderates away or simply helping Biden hold onto his existing lead …

Even more than the Democrats, Team Trump could use some clarity from the polling that will follow the Republican convention. For months, Trump has been throwing spaghetti at the wall and seeing what sticks. His allies called Harris “nasty,” “phony” and “far-left” while alleging simultaneously that she’s too tough on crime and anti-police. According to Trump, Biden is sleepy, corrupt, weak, too liberal, and harmful to God. During the party’s convention, Team Trump can try out all of these attacks and gauge which, if any of them, land. Trump may not come out of the convention with a more focused or coherent message, but his team will have a better read of what his fans — and all-important swing voters — want to hear.

It’s interesting that on night one of the RNC, we heard almost nothing about Joe Biden as senile but plenty of assertions that he’s a puppet of the far left, if not a crypto-Marxist himself. That may have been the product of some pre-convention polling or focus-group work, or simply a reaction to Biden’s performance at the DNC, which was far from sleepy or stumbling.

In any event, by next week we should know if either candidate has gotten a net convention bounce and whether their stretch-drive messaging has now taken definitive shape. And if the kind of shriek-a-thon Republicans treated viewers to on night one continues and does seem to be helping Trump tighten the race, then Lord help us all in enduring the dark and twisted road ahead.

Will Biden — or Trump — Get a Post-Convention Bounce?