Opinion | What Polls Are Telling Us as Democrats Convene in Chicago

At the Democratic National Convention this week, Kamala Harris faces a challenge. She must understand and speak to voter concerns on major issues like the economy without being downbeat. She must highlight her experience as President Biden’s right-hand woman without aiding Republicans in their efforts to link her to voter frustrations with Mr. Biden’s presidency.

Essentially, she must explain why she is the right person to tackle the problems of the next four years without being defined by the past four years.

A recent ABC News-Washington Post-Ipsos poll shows why Ms. Harris needs to seize that opportunity this week. Donald Trump maintains sizable leads over his opponent when voters are asked which candidate they trust more to handle the economy, inflation and immigration. If there’s any question about what issues the campaigns think will define the race in battleground states like Georgia, look no further than the ads being aired in the Atlanta media market: a flurry of spots about Ms. Harris’s record on the economy and immigration from both campaigns.

Yes, despite all her momentum, Ms. Harris has work to do on these issues, and normally it would be a bad sign for voters to say they think you aren’t very influential in the administration in which you serve. Yet in an environment in which voters, just a few months ago, were much more likely to say they’d benefited from Mr. Trump’s policies than from Mr. Biden’s, the ability to chart your own course as a candidate is valuable, and Ms. Harris has this blessing in disguise: In the ABC-Post poll, only 33 percent of Americans said that Ms. Harris has had “a great deal” or “a good amount” of influence over the Biden administration’s economic policies, and just 39 percent say the same of Ms. Harris on immigration. So far, Republicans’ efforts to highlight Ms. Harris’s early role as Mr. Biden’s point person on tackling drivers of migration across the southern border don’t seem to have had the kind of effect they want — probably need — it to.

Ms. Harris remains, for the moment, something of a blank slate to many voters. According to the latest CBS News-YouGov polling, more than one in three voters say they don’t know what Ms. Harris stands for, far more than say that about Mr. Trump. (The Democratic Party itself seemed to be behind the times, putting out a platform just before the convention that repeatedly referred to a Biden second term.)

Indeed, the most recent shifts in the race seem to be much more about voters’ changing attitudes toward Ms. Harris than any re-evaluation of Mr. Trump. In the ABC-Post poll, Mr. Trump has actually gained a point since July, when he was at 43 percent in a multicandidate field including Biden; today he is at 44 percent in a field that includes Ms. Harris and others. Nevertheless, Mr. Trump went from a slim one-point margin over Mr. Biden to a three-point deficit to Ms. Harris, with the vice president seemingly absorbing a chunk of voters who may have previously been undecided or leaning toward a third-party candidate.