Vice-President Kamala Harris and former President Donald J. Trump are carrying out a virtual house-to-house hunt for the final few voters who are still up for grabs, guided by months of painstaking research about these elusive Americans.

Inside the Delaware headquarters of Harris’s campaign, analysts have spent 18 months curating a list of which television shows and podcasts voters consume in the battleground states. Her team has assigned every voter in these states a “contactability score” from 0 to 100 to determine just how hard that person will be to reach — and who is best to deliver her closing message.

The results are guiding Harris’s media and travel schedule, as well as campaign stops by brand-name supporters. For instance, the movie star Julia Roberts and the basketball great Magic Johnson earned high marks among certain voters, so they have been deployed to swing states.

At Trump’s headquarters, in South Florida, his team recently refreshed its model of the battleground electorate and found that just 5 per cent of voters were still undecided, half as many as in August. The Trump team calls them the “target persuadables” — younger, more racially diverse people with lower incomes who tend to use streaming services and social media. Trump has made appearance after appearance on those platforms.

This furious search for a fickle sliver of the country has grown more urgent because the presidential contest is as close as any since the advent of modern polling, with the two candidates nearly deadlocked across the battleground states. The election could now ride on undecided Americans who have unplugged almost entirely from political news — making them tricky to find even for billion-dollar campaigns.

“These people are not super political,” said James Blair, the political director of the Trump campaign, “and so we’re doing non-super-political media.”

In interviews, senior Harris and Trump advisers divulged some details of whom, exactly, they still view as up for grabs. Both see a group that is younger, with a disproportionate share of Black and Latino voters. The Harris campaign believes it can still win over some white college-educated voters, particularly women, who have voted Republican but are repelled by Trump.

An analysis of polling in the battleground states from The New York Times and Siena College found that a mere 3.7 per cent of their voters, or about 1.2 million people, were still truly undecided.

The Times analysis closely mirrored what the campaigns describe: a group heavy on younger voters, people of colour and those without college degrees. Black voters make up about 21 per cent of the undecideds, which helps explain Harris’s explicit push for them.

Many undecided Americans are unsure if voting is even worth their time.

“I’m not seeking out a ballot to vote because I don’t care,” said Kyler Irvins, 22, a telehealth specialist from San Tan Valley, Arizona, in the Phoenix area, who has never voted and said he registered only at his mother’s insistence.

He did not watch the debates, does not follow news coverage and does not believe his vote will make a difference. But he did say he remembered the pride he felt when, as a Black elementary school student, he watched Barack Obama win the 2008 election.

Yet the campaigns and their allies are spending hundreds of millions of dollars in these final weeks to persuade people like Irvins to vote — and to choose their side.

“If the mail-in ballot comes, I’ll send it in for Kamala,” Irvins said. “If it comes to my front door.” The Harris campaign considers its audience of winnable swing voters to be up to 10 per cent of voters in battleground states, slightly larger than what the Trump operation sees for itself or the Times polling indicates.

That is because the campaign includes a large number of Republican women who it believes dislike Trump, particularly on abortion policy, but want to hear Harris’s message on the economy and the border before they are persuaded. This strategic thinking has informed her campaign speeches. On Thursday in Wisconsin, she made a direct call to Republicans, particularly those put off by Trump. She reminded the audience that she had the backing of Liz Cheney, the conservative former congresswoman from Wyoming.

New York Times News Service