Will the DNC shake up the polls in Harris’s favor? 

Now that the Democratic National Convention has ended, the overarching question is whether Vice President Kamala Harris did enough to permanently move the needle in what figures to be an extremely close presidential election. 

Put another way, while Harris is almost certain to see a post-convention bump, will the vice president be able to sustain the momentum the way former President Bill Clinton did in 1992? 

Back then, Clinton went from trailing then-President George H.W. Bush 48 percent to 40 percent on the eve of the DNC to leading 56 percent to 34 percent shortly after, never to trail again. 

Or will Harris’s vulnerabilities prove too hard to overcome, just as former Secretary of State Hillary Clinton’s were? In 2016, she saw a significant 8-point post-convention bump, but ultimately could not prevail over former President Donald Trump. 

While it is too soon to know the full impact Harris’s DNC performance will have on the polls, by virtually any metric, the convention — and her address — were a success. 

In a riveting and compelling speech, Harris outlined a centrist agenda focused on her vision for the future, defining herself as a middle-of-the-road Democrat all voters could relate to. 

She addressed, head-on, how she will approach key issues such as abortion, the southern border, the economy, crime and foreign policy. And, in her attacks on Donald Trump, Harris introduced herself to voters as a fighter. 

Party-wide, Democrats showed a great deal of unity in Chicago, and the enthusiasm behind Harris was palpable.  

The question remains however, will it be enough to move the needle in a significant and lasting way in Harris’s direction?

The electorate is much more polarized now than in 1992, meaning there are fewer potential swing voters to be impacted. But Harris’s upbeat performance, speaking to issues such as standing up for the middle class and abortion, will be a test of whether a well-orchestrated convention can affect strongly held voter attitudes.  

Ahead of the convention, polls suggested that, in the absence of a well-defined agenda and the limited time Harris had to introduce herself to voters, much of the momentum was due, simply, to who she was not. 

Prior to President Biden’s withdrawal, just one-fifth (20 percent) of Democrats said they were satisfied with the choice of Biden or Trump, per an ABC News/Ipsos poll. 

With Harris atop the ticket, that jumped to 60 percent of Democrats saying they are satisfied with the matchup. Notably, there was also an 11-point increase (19 percent to 30 percent) in independents saying they are satisfied compared to when Biden was the nominee.  

Key Democratic voting blocs are also rallying around the vice president in a way they simply were not behind Joe Biden. 

Between July and August, there was an 11-point increase in voters under 40 years old saying they support the Democratic nominee, and a 4-point increase in the share of both Hispanic and Black voters saying the same. 

In that same vein, more than 6 in 10 (62 percent) Democrats said they were “strong” Harris supporters, almost double the number who had said the same of Biden in previous polling conducted by ABC/Ipsos.  

Harris’s personal metrics, such as her favorability, had also seen a significant improvement in the days ahead of the DNC, reaching a record-high 50 percent favorable versus 45 percent unfavorable, according to Morning Consult. 

That being said, despite the successful convention and a likely post-convention polling boost, it is an open question whether Harris did enough to overcome the vulnerabilities that were evident in pre-convention polling. 

As one of us wrote in the Hill last week, multiple polls conducted before the DNC reflected that, on the issues that will define the election — the economy and inflation, immigration, crime and foreign policy — voters tended to prefer Donald Trump. 

According to Ipsos polling, voters trust Trump over Harris to address inflation (41 percent to 32 percent), immigration (44 percent to 27 percent), and foreign policy (38 percent to 29 percent). 

Further, an Economist/YouGov survey, which came out during the DNC, points to potential weakness for Harris outside of the Democratic base. Asked whether they would or would not consider voting for Vice President Kamala Harris, a majority (53 percent) of independents said they would not. 

Similarly, the aforementioned ABC poll suggests that while rallying traditionally Democratic voters, Harris has not yet improved on Biden’s 2020 margins with two key voting blocs. 

The vice president’s 5-point lead with suburban voters (50 percent to 45 percent) is roughly half of Biden’s 11-point advantage in 2020, and her 34 percent support among white non-college voters is virtually identical to Biden’s 33 percent four years ago, according to Pew Research. 

How opinions of the vice president change among these two groups of voters will be critical to watch, particularly after a successful DNC. If Harris can move the needle in her direction with these key groups, the vice president’s honeymoon period may, in fact, last through the 2024 election. 

Douglas E. Schoen and Carly Cooperman are pollsters and partners with the public opinion company Schoen Cooperman Research based in New York. They are co-authors of the book, “America: Unite or Die.”