The results are in: Donald Trump's modest post-convention bounce was wiped out by Hillary Clinton's larger post-convention bounce. Now practically all convention news has been wiped out by Trump's own erratic behavior. Listing everything, uh, mercurial, he's done since Philly would alone take up my allotted word count. (For a good recounting, read this.) These last two weeks are a perfect snapshot of the volatility of 2016, and Trump's knack for self-sabotage.
Many Democrats and the press watched the Republican convention in horror—agog at Trump's reliance on racially coded tropes, dark, depressing language, and a dearth of A-grade surrogates not named Trump. Yet polling conducted by my firm—PSB Research—showed not only a post-convention bounce, but in fact strong positive reaction to speech highlights. We tested four clips—from the speeches of Ivanka Trump, Ted Cruz, Mike Pence, and Donald Trump—and all were well-received. After each clip, more respondents said they became more likely to vote for Trump than not. And after viewing all four clips, Trump's post-convention bounce moved from + 3 points to + 6 points.
We did a comparable exercise after the Democratic convention, and found Clinton earning an 8 point bounce from after Cleveland. She too, was able to move voters further after we showed four clips (from Michelle Obama, President Obama, Michael Bloomberg, and Clinton herself). And her post-clip movement was the same (+3 points) as Trump's in our post-Cleveland survey.
But what makes Clinton's bump perhaps more likely to stick is Trump's own self-sabotage. He counter-programmed during his convention, unable to pass up a chance to go on the Golf Channel or call into Fox News. He stepped on his own convention bounce to attack Ted Cruz's father. And he stepped on Clinton's arguably shaky interview on Fox last weekend to attack grieving parents and demonstrate his lack of foreign policy chops.
So by now we've learned two things: First, there is no polling that can move quickly enough to reflect the Twitter-speed of Trump nuttiness. And what roils the press takes far longer to penetrate the national consciousness. Second, when he's coherent, Trump has a message that actually appeals to a politically divided country. Despite his many, many, well-enumerated flaws, he still garners support, and his prepared speeches have an impact. Unfortunately, he's rarely coherent, and his preferred core message is insults and nonsense. And that, thankfully, won't help him grow further.
But his outlandish behavior doesn't just limit his ceiling, it could lower it. Trump is turning off Republican leaders, operatives, donors, and the press. For sure many voters are sick of politics as usual, and welcome a candidate freed from kowtowing to the establishment.
However in practice this latest crazy-spree means Trump is poised to get few major newspaper endorsements, to alienate the kind of top-tier talent unlikely to make rookie mistakes, to be unable to put together the data and turnout operation required to win in November, and to even have most members of his party refuse to share the stage with him. There may be some voters who want to give Trump the benefit of the doubt; but Trump seems completely unwilling to capitalize on his own success.