Can Kamala Harris beat Donald Trump?

It is a fairly universal truth of journalism that if an article has a question mark in its headline it indicates that the author does not know the answer. As an editor, I often found this tendency maddening, though not always avoidable.

In the case of making judgments about an American presidential election that is still more than 100 days away, and about a candidate who has had barely four days in which to make an impression, the question mark is, however, justified.

What we can do at this early stage in what is now a Harris-Trump contest is to identify strengths and weaknesses, pitfalls and opportunities.

In opinion polls, it is clear that, when asked before Biden’s withdrawal whether or not they would choose Harris over Trump in a two-way contest, Harris scored better with respondents than Biden but not by much. However, two caveats have to be applied to those polls. The first is that questions about hypothetical pairings have not proved to be reliable indicators in the past once the hypothetical became real.

The second, which would have applied to Biden-Trump, too, is that, in the nature of things, most American voters do not think seriously about which choice they will make until after Labor Day in early September, if then.

For Biden-Trump, however, there was a caveat against that caveat: since this was to be a re-run of 2020, voters arguably already knew everything they were ever going to know — or want to know — about those two candidates, so judgments recorded in June or July might have been more dependable than for previous campaigns.

And the key thing they knew about Biden — that he was 81 years old, and showing signs of his age — was not going to change.

So a crucial issue must be whether voters already feel