Candidates step up their attacks after Trump erases Harris’s lead

ATLANTA—Democrat Kamala Harris is courting a narrow slice of undecided, GOP-leaning voters while trying to turn out her party’s base in the final stretch of the presidential campaign, as Republican Donald Trump doubles down on his strongest supporters with off-script moments that have threatened to overshadow his closing arguments.

People close to the campaigns believe the race is still too close to call a clear leader, with early voting under way. Across the seven most watched battleground states, more than 4.8 million people have already cast ballots, according to a University of Florida database. Polls show a neck-and-neck race just over two weeks until Election Day, after Trump clawed back a polling advantage Harris enjoyed in the wake of their only debate.

Trump’s strategy has been to use a series of events that can be unconventional, often mixing humor and tough, sometimes crude, talk that plays to his most ardent backers, particularly men. Vice President Harris’s tack, meanwhile, seeks to peel away Republicans and independents from Trump by alleging he is unfit to serve while also corralling a fractious Democratic coalition that has spent much of the year torn apart over Israel.

Harris, who sharpened her criticisms of Trump over the weekend, is expected to hold events on Monday with former GOP Rep. Liz Cheney in suburbs in Pennsylvania, Michigan and Wisconsin that have been shifting away from the Republican Party. She is also hosting separate get-out-the-vote rallies later in the week with former President Barack Obama and first lady Michelle Obama in Georgia and Michigan—swing states where Harris needs to run up large margins in the urban centers and suburbs.

Her objective is rooted in the campaign’s analysis that has found a chunk of remaining undecided voters to be soft GOP-leaning voters and moderate independents, according to a person familiar with the data. Those include voters who backed former South Carolina Gov. Nikki Haley over Trump in the GOP primaries. Harris’s advisers believe drawing a sharper contrast with Trump—including warning against the dangers of giving him a second term—can pull in those undecided voters while also exciting liberals.

This continues Harris’s tactic in recent days to try to court GOP-leaning voters and independents, which is one reason she sat for a Fox News interview that featured a heated back-and-forth on immigration.

Pointing to the Republicans who have endorsed her, Harris said Saturday at a rally in Atlanta: “Folks are exhausted with someone trying to have Americans point their fingers at each other.”

Democrats said Harris’s outreach to Republicans could prove worth it—as long as it doesn’t take away from the core Democratic coalition. Some polls have shown a lack of enthusiasm for Harris among Black and Latino men in particular.

“Overall, her strategy is to build an even bigger tent,” said Quentin James, founder and president of the Collective PAC, which is working on getting Black men to the polls in swing states. “She is doing both well at the moment” but needs to home in on base Democratic voters in coming days, James said.

Trump campaigned at a McDonald’s in Pennsylvania on Sunday, trying to raise doubts over Harris saying she worked there in her youth. He removed his suit jacket, donned an apron and made french fries, then poked his head out of a drive-through window to serve prescreened customers. “I wouldn’t mind this job,” he said. Outside, swarms of people lined the streets.

The Harris campaign has said Harris worked at an Alameda, Calif., McDonald’s restaurant over the summer while in college, but it hasn’t disclosed specifics such as length of employment or which franchise.

The visit was part of a string of stops Trump has made—he was at a barbershop in the Bronx on Thursday—designed to show him as relatable to everyday people. His campaign basks in the unpaid media attention generated by the events. Later Sunday, Trump planned to attend the Pittsburgh Steelers game.

This coming weekend, Trump has a rally at Madison Square Garden in New York City. New York isn’t a battleground, but Trump has long wanted to hold a rally in the famed arena, and aides are planning a blockbuster with special guests.

Even as Harris recently tried to characterize Trump as exhausted, he has an increasingly packed schedule and this week will court religious leaders and Hispanic voters while stopping in several swing states, including North Carolina, Georgia, Arizona, Nevada and Michigan. His campaign has flooded the airwaves with ads criticizing Harris for past comments about taxpayer-funded surgeries for transgender prisoners. And it is banking on his continued advantage over Harris on the economy, the top issue for voters.

In a sign of the manic nature of the campaign, over the weekend Trump ally Elon Musk unveiled a $1 million a day lottery for registered voters in key states who sign his free-speech and gun-rights petition. Critics say the effort could run afoul of federal law by offering an inducement for people to register. A Musk attorney didn’t immediately respond to a request for comment about the matter.

Trump has been doubling down on catering to his base on issues such as immigration while continuing to provide flashes of controversy and oddity. Though the Trump campaign, according to aides, has been in conversations for a joint appearance with Haley, Trump has instead reminded voters in recent days about how he defeated her resoundingly.

The former president also began a Saturday rally in Latrobe, Pa., with a ribald tribute to the late golfer Arnold Palmer, who was born in the city. “When he took showers with the other pros, they came out of there, they said, ‘Oh my God, that’s unbelievable.’ ” The crowd behind him snickered.

Aides said Trump would use the event to begin making his closing argument, that Harris hasn’t earned a promotion.

“You have to tell Kamala Harris that you’ve had enough, that you just can’t take it anymore, we can’t stand you anymore, you’re a s— vice president,” Trump said. “The worst. You’re the worst vice president. Kamala, you’re fired. Get the hell out of here.”

The episode came on the heels of another odd campaign event last Monday in Pennsylvania. After audience members needed medical attention, Trump decided to turn the event into a concert, ordering up some of his favorite songs to be played while he listened along and danced a little.

To Trump’s supporters these off-script moments—often delivered during long, meandering speeches—are evidence he isn’t a cookie-cutter politician and can show a sense of humor.

“The media can pick it apart,” said House Speaker Mike Johnson (R., La.) on CNN. “But people are going to vote. They’re going to vote what’s best for their family, and they see that in Trump.”

But some Republican allies are concerned that he is creating distractions at a crucial time, while Harris has used the moments as an opportunity to portray Trump as unstable.

“Have you noticed he tends to go off script and ramble and generally for the life of him can’t finish a thought?” Harris said in Atlanta over the weekend. “He has called it a weave. We here call it nonsense.”

At another stop at a union hall in Lansing, Mich., Harris showed video footage of Trump complaining about paying overtime and saying that U.S. auto workers’ jobs could be done by children. It was part of her more tailored pitch to blue-collar voters, following concerns from some Democrats who have pushed her to make more direct appeals to those voters.

“Listen to his words,” Harris said to several-hundred union workers gathered at the UAW hall. “He’s got his club, and I’m going to tell you, union workers are not part of his club.”

Annie Linskey and Jimmy Vielkind contributed to this article.

Write to Tarini Parti at tarini.parti@wsj.com and Alex Leary at alex.leary@wsj.com