WASHINGTON — As she abruptly went from No. 2 on the Democratic ticket to No. 1, Vice President Kamala Harris had a decision to make: How should she deploy President Joe Biden on the campaign trail?

Given that Democrats had pushed Biden out because of concerns about his age, mental fitness and ability to defeat former President Donald Trump, would she be best off distancing herself from the 81-year-old president and focus instead on establishing her own political identity? Or should she continue to embrace Biden and the more popular of his policies?

And on the most practical level: Where should Biden go to campaign for her? How often? And what should he say?

Her answers are now starting to emerge. Harris and the people running her campaign plan to use the president — but carefully, and in a targeted way. The president and vice president will campaign together some, but not too much. And Biden will travel mostly to the important swing states of Pennsylvania, Wisconsin and Michigan, where he still appeals to white, working-class voters and union members.

“He gets an enormous amount of credibility in those blue wall states because he’s ‘Workin’ Joe Biden,’ ” said Cedric Richmond, a former administration official who is now advising Harris’s campaign. “People are underestimating the Democratic Party’s love for Joe Biden. It just highlights how many different messages he can give and the different places he can go.”

That strategy will be on display almost immediately.

On Monday, the president will join Harris at a union- focused Labor Day campaign event in Pittsburgh.

On Thursday, Biden will be in Wisconsin to tout his administration’s investment in communities there. On Friday, he will travel to Michigan with the same message.

Campaign advisers to Harris and Biden’s aides in the White House — who are carefully coordinating their decision-making — have decided there is no real advantage for the vice president in making a clear, public break with the president or his policies.

Ben LaBolt, communications director at the White House, said Biden would be “leaning in heavily” on the effort to get Harris elected.

In an interview Thursday on CNN, Harris showed every indication that she intends to embrace her boss.

“History is going to show,” she said, “not only has Joe Biden led an administration that has achieved those extraordinary successes, but the character of the man is one that he has been in his life and career, including as a president, quite selfless and puts the American people first.”

But polls consistently show that many voters are not eager for a reminder of the past, whether it is a return to Trump’s presidency or Biden’s. The president’s approval rating in Michigan is just 38%, according to a New York Times/Siena College poll in early August, and just 42% across Michigan, Pennsylvania and Wisconsin combined.

As a result, people close to Biden say he and Harris are unlikely to campaign together much in the weeks ahead. Campaign officials say they will “divide and conquer” by traveling separately to spread the campaign message.

Veterans of presidential campaigns in both parties said the trickiest part about deploying Biden on the campaign trail is making sure that his message — and the way he delivers it — does not undercut Harris’s all- important task of convincing voters that she represents a new and different future.

“The last month has shown you that the appetite for turning the page from Biden, while still genuflecting toward and appreciating what he did to win in 2020, is so hot,” said Kevin Madden, who was a top strategist for Sen. Mitt Romney, R-Utah, during his 2012 presidential campaign against President Barack Obama.

“Every election is a contest for the future,” he added. “So they really do have to be focused on making a case for what Harris would do the next four years as president.”

The goal, several advisers said, is to have Biden talk mostly about his record of accomplishments while in office: lower prices for some prescription drugs, investments in infrastructure and computer chips, an increase of 15 million jobs and an economic recovery from the COVID-19 pandemic.

They also said Biden can be helpful by continuing to do his day job, which they believe serves as a daily contrast to the kind of nastiness and chaos that permeated the Trump White House.

“Biden can describe the mess and he can describe the cleanup in a way that no one can match,” said Pete Brodnitz, a veteran Democratic pollster who is not working for Harris. “I think that is really useful.”