New York Times

With President Biden no longer in the race, former President Donald J. Trump would be the oldest person ever to serve in the Oval Office. But his rambling, sometimes incoherent public statements have stirred concern among voters.

Heading into the high-stakes debate on Tuesday, the mood in the party remains upbeat. But with polls looking tight, concerns are starting to seep in.

In the seven weeks they have been campaigning against each other, the vice president and the former president have attacked each other on social media dozens of times. Only Mr. Trump frequently gets personal.

At Tuesday’s debate, Kamala Harris, the vice president, will try to promote herself as a change candidate without criticizing President Biden, whom she has served for years.

As the candidates meet for their only scheduled debate on Tuesday night, here is what to be on the lookout for.

The survey finds that Donald J. Trump is retaining his support and that, on the eve of the debate, voters are unsure they know enough about where Kamala Harris stands.

The candidates are all but certain to clash over the issue, which Kamala Harris sees as a major strength. Donald Trump may try to avoid political blowback for his approach.

Kamala Harris’s razor-sharp debate skills have powered her political ascent. Her success next week will turn on how well she adapts to an unpredictable rival.

Kamala Harris is camped out at a Pittsburgh hotel. Donald Trump is being peppered informally by aides. Both sides share the same belief about why the debate is so crucial.

We took photographs, captured 360-degree video and counted attendees at six recent rallies to analyze which of the candidates’ claims on crowd sizes hold weight.