WASHINGTON — It should have been an easy question.
In Guatemala this week, Vice President Kamala Harris sat with NBC anchor Lester Holt, who grilled her about why she had not visited the U.S.-Mexico border as part of her work examining the root causes of migration. After the third border-related question, the vice president appeared to have had enough.
“I’ve never been to Europe,” Ms. Harris said. “I don’t understand the point you’re making.”
That response perplexed several administration officials who knew she had prepared at length for the question. By veering away from the script, Ms. Harris gave Republicans grist for a news cycle that lasted longer than her two-day trip. In another appearance, her blunt message to migrants on behalf of President Biden — “do not come” — was criticized by lawmakers in the progressive wing of her own party.
The trip crystallized something crucial about Ms. Harris’s vice presidency: Whether she stays on message — as she did by telling migrants not to come — or goes off script, she will not be able to satisfy everyone. With two of the most polarizing issues, migration and voting rights, now in her portfolio, the risk of missteps is so high and the problems so intractable that even her allies say she is in a no-win situation.
A politician who has always struggled to define herself, Ms. Harris is now trying to do so in real time, with two issues that could complicate her own political future and potentially upend some of Mr. Biden’s central ambitions for his legacy.
“They’ve just been flat-footed on immigration and they’ve opened up a significant political vulnerability for themselves,” Richard N. Haass, the president of the Council on Foreign Relations, whom Ms. Harris turned to for foreign policy advice during the general election, said of the Biden administration’s approach to responding to a surge of migrants at the border. “It was her bad luck that this is her assignment. She can’t succeed given these circumstances.”
(As for her “Europe” comment, Mr. Haass had one word: “Inartful.”)
Her aides say the criticism should not overshadow a trip that, from a policy perspective, delivered on its diplomatic and economic goals. Officials on the National Security Council are still flooding her with requests for more foreign travel, viewing her presence in the Northern Triangle countries of Honduras, El Salvador and Guatemala as a plus for the administration.
Ms. Harris is aware of the stakes involved.
According to interviews with 20 White House aides, allies and former advisers, Ms. Harris is trying to shape her vice presidency by tackling unwieldy policy issues, developing relationships she was not known for nurturing as a senator and adhering to the president’s goals, even if some of what she is saying now contradicts what she said she used to believe.
“That’s the role she signed up for,” Gil Duran, a Democratic strategist and former aide to Ms. Harris, said in an interview. As a senator, Ms. Harris signed a letter criticizing the Trump administration’s use of a public health rule to turn away asylum-seekers at the border, a position at odds with the Biden administration’s current policy.
But Mr. Duran pointed out that the reception by Democrats to the Biden administration’s warnings to migrants “might look very different in a general election in the future, and that’s the audience she’s playing to now.”
A charismatic senator who entered the 2020 presidential election eliciting comparisons to Barack Obama, Ms. Harris didn’t make it to the Iowa caucuses partly because she never knew which issues to emphasize. As vice president, Ms. Harris began her tenure as a generalist, in large part to learn the rhythms of a president she was still getting to know.
At first, she had two options, drawn up by Ron Klain, Mr. Biden’s chief of staff. She could develop a narrow portfolio, diving deep into a few specialized issues. Or she could spend most of her time with Mr. Biden. Ms. Harris, who since joining Mr. Biden on the ticket has been eager to prove herself a team player, eagerly chose the first option.
When Mr. Biden decided to assign her the Northern Triangle — a task he had accepted during his eight years as vice president to Mr. Obama — it was seen as “taking one for the team,” said one of her former aides, who spoke on the condition of anonymity to preserve relationships.
Over a month ago, Ms. Harris began having conversations with both the president and Mr. Klain about another area where she felt she could be effective. She had worked on voting rights legislation in the Senate, and had co-sponsored two of the expansive bills that were foundering in the chamber. And, as the first Black woman and woman of Asian descent to hold her office, the topic was personally important to her.
She told Mr. Biden she would be happy to take the lead on the issue. Mr. Biden agreed.
“I’m glad she is not waiting for someone to put on her plate what should be on her menu,” said Donna Brazile, who managed Vice President Al Gore’s 2000 presidential campaign. “I can’t think of a better issue for her.”
The challenges of Ms. Harris’s new role presented themselves almost immediately: Senator Joe Manchin III of West Virginia, who is perceived as a pivotal moderate holdout who could help his fellow Democrats pass an expansive voting rights law, publicly said last week that he could not support it.
He also said he was against eliminating the legislative filibuster, a promise that imperils much of the Biden administration’s agenda, including voting rights.
Mr. Manchin’s decision laid bare for Ms. Harris another political reality: She did not have strong enough relationships with key lawmakers to negotiate on that issue, or on several others facing the administration.
Ms. Harris, who spent a chunk of her four years in the Senate running for president, was not known for building especially close relationships with her colleagues, and Mr. Manchin was no exception. She has not acted as one of the administration’s lead negotiators on the American Rescue Plan that Mr. Biden signed into law in March or the American Jobs Plan, his infrastructure proposal.
Recently, she has tried to do more outreach to her former colleagues. Next week, she will host a bipartisan dinner for all 24 women senators at her official residence on the grounds of the Naval Observatory, her first social event since moving in.
With the passage of any legislation on voting rights looking less likely, many Democrats expect Ms. Harris will play a role in marshaling civil rights groups, private companies and community leaders to beat back hundreds of restrictive laws introduced in Republican-led state houses across the country. Next week, she will host a group of Texas Democrats who last month blocked the passage of legislation that would have made it harder for Texans to vote.
“You’re going to need a high-profile surrogate saying, ‘They did this on purpose and you must turn out to vote.’ That may be what she ends up doing,” said Jennifer Palmieri, who served as White House communications director under President Barack Obama.
Many of her predecessors struggled with the limitations of the vice presidency, but Ms. Harris, the first woman of color in her position, encounters a different sort of scrutiny. She has become a target of attacks from conservative media outlets, which so far have not figured out a way to attack Mr. Biden head-on. And every action of hers is being viewed through the lens of her own political future. In choosing her as his running mate, Mr. Biden essentially anointed her the leading Democratic candidate to succeed him.
For now, though, Ms. Harris is still learning to play a role that her boss knows better than almost anyone.
Aware that he made a big investment in Ms. Harris by choosing her as his vice president, Mr. Biden has made sure she receives the same briefing materials he does, and folds her into most of his meetings, because, as one White House official put it, he wants her to absorb his way of thinking. They both receive their daily briefings and media clips on iPads.
Ms. Harris has a weekly one-on-one meeting with Mr. Klain as well, a level of inclusion in the day-to-day work of the White House that Biden aides point out was never offered to Mr. Biden when he served as vice president.
“The vice president’s job is such a hard one because the advice you give is unseen and the tasks you perform are totally at the discretion of the president and his staff,” said David Axelrod, a former top adviser to Mr. Obama. “For politicians accustomed to leading roles, it can be very frustrating.”
As vice president, Mr. Biden was known for stepping outside of the boundaries of his office, sometimes getting ahead of Mr. Obama on hot-button issues, including gay marriage. Ms. Harris has made no such missteps, but does take note of the criticism she receives.
Ms. Harris is quick to laugh in interviews, a tendency that has earned her unflattering headlines. In March, a misleadingly edited video that appeared to show her laughing about the plight of children at the Southern border gained attention online, frustrating Ms. Harris and people close to her. It happened again this week, when she was asked about the border by Mr. Holt, and a wave of criticism followed.
“That message was sent loud and clear that she really doesn’t care,” said Brandon Judd, the president of the National Border Patrol Council, referring to the NBC interview.
Because she pays close attention to her own media coverage, Ms. Harris has gone to her allies with some version of the same question, according to several people briefed on internal exchanges: Should I never laugh?
“Women, especially women in executive positions, get judged far more harshly, and that is a reality,” said Anita Dunn, a senior adviser to President Biden. “Of course she’s aware of that.”
The president’s advisers say he is pleased with how Ms. Harris’s trip went. Ms. Dunn pointed out that Mr. Biden called the vice president on Friday, while he was abroad on his own first foreign trip, to congratulate her on her work.
“She’s never going to get an easy issue,” Ms. Dunn said, “and neither is the president of the United States.”
Zolan Kanno-Youngs contributed reporting.