Harris leads Trump in the polls – here’s what they really tell us about her chances

Poll data shows that Kamala Harris now leads Donald Trump in the US presidential election campaign. She has an average vote intention score of 48.2%, compared with Trump’s 45.8%, according to FiveThirtyEight, a website that looks at a range of polls.

She leads in the race, although the margins are still tight. A poll of polls like this one is likely to be more accurate than a single one, giving a much better indication of any trends.

Many factors are at work when people decide how to vote, but four things really matter. These are voter evaluations of the candidates; their perceptions of the major issues; identifying with the Democratic or Republican parties, or being independents; and whether they think of themselves as liberals, conservatives or moderates.

To look closely at these factors we can examine the details of an Economist/YouGov survey of the US electorate completed on September 17. The survey puts Harris on 49%, with Trump on 45% in voting intentions.

There are significant variations in support among different groups and as the figure below shows, there is a large gender gap with women much more likely to vote for Harris than men. In addition, white people favour Trump, whereas Hispanic and black people lean heavily towards Harris. Harris is also strongly supported by those under the age of 45 with Trump leading Harris by a small margin in the 45-64 group – and by a large margin among the over 65s.

Voting intentions for the upcoming US election:

When it comes to judging candidates, voters use several criteria including perceptions that they are strong, competent, honest and in touch with people like themselves. But a good overall measure is the extent to which they like or dislike a candidate. In the Economist/YouGov poll 48% liked Harris and 47% disliked her. In Trump’s case 42% liked him and 55% disliked him. Clearly, Harris has the edge in leadership evaluations in the race.

Existing ideological positions are a very important factor in influencing the vote as the chart below shows. When it comes to ideological preferences liberals overwhelmingly support Harris and conservatives do the same with Trump.

However, 57% of moderates favour Harris compared, with only 30% who favour Trump. Trump’s problem is that his style of campaigning may energise his core supporters, but it tends to alienate many moderates.

In the case of political partisanship, again Democrats overwhelmingly support Harris and Republicans Trump. In this case the independents are neck and neck, with Harris ahead of Trump by only 1%. But she does get more Republicans (5%) than Trump gets Democrats (1%).

Voting intentions among independents and other groups

Harris has the edge when it comes to three of the really important factors that explain voting behaviour. However, she is weak on some issues compared with Trump. When asked about their most important issue, respondents ranked inflation first, immigration second, and jobs, the economy and abortion tied in third place.

The problem for Harris is illustrated by the most salient issue of inflation. Some 96% of respondents thought that this is important, but only 33% approved of the way that Joe Biden had handled the issue, compared with 59% who disapproved.

Since Kamala Harris is the vice-president, she shares responsibility for this. That said, 56% think that Trump’s claim that Haitian immigrants are eating pet dogs is false, while 27% think it is true. So there is a question over his credibility when it comes to issues as well.

More generally, 25% approved of the general direction the country was headed, while 58% thought that America was on the wrong track. When asked if they felt better off or worse off than a year ago, only 12% said better off, 42% said about the same and 40% said worse off. The US economy has been growing rapidly since Biden took office, but clearly many voters still don’t feel the benefits.

Biden stepped down as the Democratic nominee for president following his disastrous performance in the debate with Donald Trump. But the polling shows that discontent with the Biden administration was a lot more widespread than just concerns about his age and ability to communicate.

In relation to the recent TV debate, 56% of respondents thought that Harris won, compared with only 27% who thought the winner was Trump. As a result, she has made a strong start to her campaign. When asked who they thought would win the election in November, 42% said Harris and 32% Trump with 26% unsure.

With that kind of momentum, Harris can be optimistic, though not certain, about the outcome.