In recent weeks, Vice President Kamala Harris has dashed off to Florida on short notice. She sparred with the state’s conservative governor, Ron DeSantis, over how to teach slavery in schools. And she flew into Iowa to defend abortion rights while 13 Republican presidential candidates were having dinner a few miles away.
Although her words were directed at Republicans, her message was also aimed at all her doubters.
Once a rising star as a senator in California, Ms. Harris has for years been saddled by criticism of her performance as vice president. She has struggled with difficult assignments on issues such as the roots of illegal migration and the narrow path to enduring voting rights protections. Concerns about her future spread as Democrats pondered whether she would be a political liability for the ticket.
Ms. Harris’s recent moves are her latest attempt to silence those concerns and reclaim the momentum that propelled her to Joseph R. Biden Jr.’s side as a candidate and into the White House in 2020.
“It’s good to have her out there,” said Cedric Richmond, a senior adviser for the Democratic National Committee, who added that the vice president’s decision to take on the Republican Party — assertively and in real time — was central to the campaign’s 2024 strategy.
It also keeps President Biden above the fray.
“He is still uniting the West against Russian aggression, and he’s tackling the economy and inflation,” Mr. Richmond said. “She can go highlight the accomplishments, and she can take on people like DeSantis.”
In interviews, aides and advisers acknowledge that Ms. Harris has been affected by the years of criticism. She has often approached events defensively, focusing on not making mistakes, rather than looking for opportunities to attack.
But now, galvanized by what she has described as rising extremism in the Republican Party, Ms. Harris is expanding her profile.
The tussle with Mr. DeSantis, who is struggling to break through as he campaigns to be the Republican presidential nominee, provides a glimpse into Ms. Harris’s role as something of a one-woman rapid-response operation.
When Florida last month approved an overhaul to its standards for teaching Black history, which now say middle schoolers should be taught that enslaved people developed skills that could be of personal benefit, Ms. Harris directed her staff to get her down immediately to Jacksonville, a White House official said.
She was on the ground within 24 hours, speaking to a packed audience in a historically Black neighborhood, about “extremist so-called leaders” who want to sanitize history.
“How is it that anyone could suggest that in the midst of these atrocities that there was any benefit to being subjected to this level of dehumanization?” Ms. Harris said, drawing a standing ovation from the crowd.
Her appearance caught the eye of Mr. DeSantis.
“You clearly have no trouble ducking down to Florida on short notice,” he said in an open letter last week, accusing her of trying to score political points and inviting her to discuss the new standards.
Ms. Harris, who returned to Florida for her second trip in less than two weeks, had a swift reply.
“Well, I’m here in Florida,” she said before pausing as the crowd at an African Methodist Episcopal Church event in Orlando erupted in applause. “And I will tell you, there is no round table, no lecture, no invitation we will accept to debate an undeniable fact: There were no redeeming qualities of slavery.”
The vice president’s press secretary, Kirsten Allen, said Ms. Harris would “continue to call out extremist leaders as they attempt to pull our country backward with book bans, revisionist history and barriers that make it harder for Americans to participate in our democracy.”
Despite her more public role, Ms. Harris’s approval ratings have remained stubbornly low. About 52 percent of Americans have a negative view of her, while 40 percent have a positive view, according to FiveThirtyEight’s poll tracker. Mr. Biden has also had trouble with persistently low approval ratings.
But Ms. Harris connects to sections of the electorate that are not always a natural fit for Mr. Biden, including women, minority groups and younger voters. At 58, Ms. Harris is decades younger than the 80-year-old president, who would be 86 at the end of a second term.
As Ms. Harris fans out across the country, some of her longtime allies said she was showing the kind of swagger they remembered from much earlier in her career, dating back to her days as district attorney of San Francisco and attorney general of California.
“Seeing her in this role, understanding she has a president who she reports to, it’s kind of funny to me,” said Lateefah Simon, who was hired by Ms. Harris in 2005 to lead a new program aimed at keeping first-time drug offenders out of jail.
She recalled a confident Ms. Harris walking through the office when she won re-election for district attorney in 2007, reminding each staffer that she would be the boss for another four years. Ms. Simon believes Ms. Harris is making an impact as vice president but wonders how she is adjusting to being second in command.
“I’m like, ‘Kamala with a boss?’” she said.
Ms. Harris often draws on her legal background on the campaign trail as a way to emphasize her expertise — a strategy that serves as a counterweight to Republican claims that she is incompetent.
At a recent speech on gun reform, she said she had studied autopsy photographs and had “seen with my own eyes what a bullet does to the human body.”
And in July, when she made a trip to Iowa for a discussion on reproductive rights, she said that she had investigated sex crimes, so she understood that denying a woman an abortion was an “immoral” approach to survivors of rape or incest.
The timing of the trip to Iowa was no accident: As she spoke at Drake University, saying opponents of abortion in state legislatures around the country “don’t even know how women’s bodies work,” former President Donald J. Trump and a dozen of his rivals for the Republican presidential nomination were in Des Moines for a G.O.P. dinner.
Her appearance came just two weeks after the state’s Republican governor signed a strict new abortion ban into law, making it illegal to have the procedure past six weeks of pregnancy. (A judge has put the ban on hold.)
Ms. Harris’s decision to go on the offensive is a notable shift.
For all of her boundary-breaking as the first woman, the first African American and the first Asian American to serve as vice president, she has long been known for pragmatism and, to her critics, for a defense of the status quo.
She has described herself in the past as a “pragmatic prosecutor” who owns a gun for personal safety and also believes in criminal justice reform. As vice president, she has had to appeal to broad constituencies; being seen as a moderate is a benefit at a time when conservative critics have tried to portray her as radical and out of step with the nation.
But now, with the campaign in full swing, the White House is giving Ms. Harris room to make more assertive moves against Republican opponents.
She also has been freed up to travel more, something that has been in the works since the midterm elections when Democrats held off a widely expected red wave.
Because the Senate was split evenly for the first two years of the Biden administration, Ms. Harris could never be more than 24 hours away from the Capitol when the Senate was in session in case her tiebreaking vote was needed.
With Democrats now holding a 51-to-49 edge, at least in cases when Senator Kyrsten Sinema, the Arizona independent, votes with them, Ms. Harris has more flexibility to move. Some are hoping she continues to seize on the opportunity.
Stefanie Brown James, a co-founder of the Collective PAC, an organization that helps elect Black officials, has urged Ms. Harris’s staff to have her out in front on affirmative action and abortion issues, in particular. She said for the past two and a half years, Ms. Harris was “a little too much in the background and not seen enough or heard enough.”
“She definitely is having a moment,” Ms. James said. But she added a note of caution, saying she hoped it would be “a sustainable moment.”