An emotional trip as the first Black US vice president to Africa, followed by a frontline role pushing President Joe Biden's economic message at home is giving Kamala Harris a chance to steady her political ship ahead of a reelection campaign set to bring fierce scrutiny.

Returning home last weekend from a tour of Ghana, Tanzania, and Zambia, Harris found herself treated to unusually positive headlines, not least in an Associated Press article, reproduced in news outlets across the United States, describing her as a "historic figure."

She hopes to carry that momentum domestically Thursday, visiting a Qcells solar panel factory in Georgia as part of an administration-wide effort to tout economic achievements in the run-up to an expected Biden-Harris 2024 reelection campaign announcement.

If Harris, 58, is having a strong moment, that hasn't always been the case since the day she arrived to great fanfare at the White House in 2021 -- the first woman and first Black person ever in the role.

The vice presidency has long been a notoriously tricky task -- a job "not worth a bucket of warm piss," as John Garner is said to have grumbled after serving in the 1930s as Franklin D. Roosevelt's veep.

Harris, however, has often come under especially harsh criticism, whether over her management style or lackluster policy achievements.

And it's a negative vibe that the White House would love to see cleared up in time for the 2024 campaign, when Harris will face an even more intense spotlight as deputy to the oldest president in history -- with Biden reaching 86 by the end of a second term.

Springing to defend Harris

The administration sprang to Harris's defense in March, after a lengthy Reuters article quoted unnamed sources saying Biden and some Democrats have been frustrated or disappointed with her performance.

Biden, marking Women's History Month, fired off a tweet a few days after the Reuters article to share effusive praise for his veep, saying he wanted to "call attention to one remarkable woman in particular: Kamala. She's shattered barrier after barrier."

The White House communications director, Ben LaBolt, also jumped on the story, dismissing the Reuters report as "silly season material."

"@VP has shaped and helped pass historic legislation that is improving lives and lowering costs for working families," LaBolt tweeted.

Harris may see better press as she pursues a steady schedule of reelection campaign travel.

And her foreign trips -- including high-profile stops in Asia -- have also bolstered her credentials should she ever have to take over in an emergency.

She matters

Vice presidents are traditionally an afterthought in Washington, but Harris, a full generation younger than Biden, brings unprecedented resonance to the old cliche about VPs being a heartbeat away from the presidency.

She also matters politically to Biden as a key part of the coalition that defeated Donald Trump in 2020.

Retaining the loyalty of Black voters -- and the symbolism of having a woman in one of the country's most prestigious jobs -- will be vital in 2024. That means the chances of Biden switching Harris for someone more popular is highly unlikely.

But whispers of discontent over her style and substance have dogged her from the start.

Pundits have criticized Harris's speech delivery since her own 2020 campaign for president, which she abandoned after gaining little traction in polls.

US media therefore took particular note when she displayed rare emotion on her Africa tour, choking up as she spoke at a one-time slavery hub in Ghana.

Given the tall order by Biden of grappling with surging illegal migration, Harris has visited Central America but not the Mexican border itself -- a public relations fail that may have owed more to restrictions placed on her from the president's office than anything else.

Wendy Schiller-Kalunian, a professor of public and international affairs at Brown University, said some of this is down to the vague mandate inherent in a VP role and some the result of poor management from above.

"It has not been clear these past two years exactly what Biden wants Harris to do," she said.

Harris has also come in for criticism of a more personal nature. A much discussed December 2021 Washington Post article quoted anonymous sources complaining of a "soul destroying" atmosphere in her office, leading to high turnover.

"Women in high levels of political office are generally subject to more intense criticism, and that is even more true for women of color," Schiller-Kalunian said.

But for Biden to have felt the need to tweet out support -- that's "troubling."

© Agence France-Presse