Team Trump might be tempted to see the Republican National Convention as that difference-maker, a week-long, wall-to-wall commercial during which Trump gets to set the political agenda rather than react to it. But wishing doesn’t make it so.
On a simple mathematical level, the convention alone is unlikely to give Trump a bounce big enough to catch up with Biden. According to polling data from the University of California at Santa Barbara’s American Presidency Project, from 1968 to 2016 presidential candidates got a average five-point bump following the convention. Biden has a roughly eight-point lead, so Trump would need an above-average boost — greater than what any candidate has earned since 2000 — to catch Biden in national polls.
As others have pointed out, Trump may not even receive the full five-point boost from his scaled-down convention. We live in an increasingly polarized era, and the number of swing voters who can be persuaded by an inspiring convention speech is decreasing. Between 1968 and 1996, the convention bounce was six points on average, and between 2000 and 2016 it was only three points. Plus, fully or partially virtual conventions likely won’t be as visually impressive as the packed arenas of previous cycles, especially if apolitical swing voters opt for Netflix or whatever professional sports are still airing instead of politics.
Additionally, the Republican convention won’t happen in a vacuum. A week before Trump and the Republicans meet, Democrats will hold their own convention, airing speeches for two hours every night. That doesn’t sound like enthralling programming, but the story the convention tells could still help define Biden in voters’ minds. As political scientists David Broockman and Joshua Kalla have demonstrated, pro-Biden ads are more likely to move voters than anti-Trump ads. A week of free airtime in which to sell the former vice president could help solidify Biden’s lead before Trump’s convention.
And even if Trump can improve his position at his convention — in 2016, he earned a slightly larger convention bump than Hillary Clinton per the UCSB data — he wouldn’t be out of the woods. Trump lacks impulse control and could easily derail any rosy news cycles that follow the convention. In the aftermath of his 2016 convention, he picked a protracted, ugly fight with Khizr and Ghazala Khan, the parents of a slain U.S. soldier.
To win, Trump probably needs not just a good convention but also Biden stumbling in debates, sustained improvements in Trump’s management of the coronavirus pandemic and signs that the nation’s economic and physical health are on their way to a lasting recovery. That’s not impossible, but hoping for two, three or four game changers is a tall order.