In the first six months of 2017, Harris has raised more than $600,000 for a dozen Senate colleagues -- including $365,000 from small-dollar online contributions, her aides said.
The email list Harris has used to raise the bulk of that money is 10 times the size it was at this time last year, during her Senate campaign. She's used that list to raise money for incumbents up for re-election in the 2018 cycle, including Missouri Sen. Claire McCaskill, Montana Sen. Jon Tester and Massachusetts Sen. Elizabeth Warren.
Harris is also planning a travel schedule in the fall to raise money for Democratic Senate incumbents as well as the challengers for seven Republican-held House seats in California that the party is targeting.
The fundraising and travel comes after a quick star turn for the freshman senator, who just took office in January.
And as the Democratic Party searches for new leaders, the 52-year-old Harris is increasingly seen as someone who could follow the rare path trodden by Barack Obama -- who was elected to the Senate in 2004 and the presidency just four years later.
Her grilling of President Donald Trump administration officials in nationally televised hearings -- which led to her twice being shushed by the Senate intelligence committee's chairman, Richard Burr -- served as her introduction to many Democrats nationally.
Those moments with Attorney General Jeff Sessions and Deputy Attorney General Rod Rosenstein also represented breakout moments for a politician who had been seen as overly cautious in her previous job as California's attorney general.
That view, her allies have long said, was largely a result of her role: Harris was keenly aware that comments potentially related to court battles and investigations could jeopardize those efforts.
"She felt, obviously, a little bit handcuffed. And now she feels like the handcuffs are off," said Sean Clegg, a long-time Harris consultant.
"The Kamala Harris that the public's seeing now is the same Kamala Harris that we've seen behind closed doors, which is a person with a strong perspective with public policy issues, who's passionate about those issues, but who's now doing a different job that's about direct advocacy and about position-taking," Clegg said. "It's almost like she's playing a different position on the floor and is showcasing parts of her game that she's always had."
Aggressively challenging Trump nominees and administration officials is advantageous for Harris in part because she represents California -- a hub of the anti-Trump resistance where Harris has little to lose in the types of moments that put her on the presidential radar.
But Harris has also demonstrated a keen understanding of what it takes to build her national profile. In part because she is new to the scene, her growth on social media far outpaces the two dominant progressive stars, Vermont independent Sen. Bernie Sanders and Massachusetts Democratic Sen. Elizabeth Warren.
Harris also sought to extend her reach beyond normal political channels. In recent days, she released a widely praised Spotify playlist
to celebrate African-American Music Appreciation Month to Blavity, a site that targets black millennials, and she wrote a scathing critique of the Senate Republican health care bill
for Lena Dunham's "Lenny Letter" newsletter.
She has also paid careful attention to growing her email list. Clegg said Harris found a 10-to-1 return on investment through Facebook advertising after the election to help build that list and raise money.
Harris plans an aggressive travel schedule in the fall to help 2018 Democratic House and Senate candidates.
Democratic operatives said those moves -- rather than trips to early-voting states like Iowa and New Hampshire -- are the right ones for any major 2020 contender in a party desperate for immediate wins and eager to reward those who are most effective at confronting Trump and delivering those victories.
"I would be as energetic as I possibly could be on behalf of 2018 candidates. Being on the road, speaking at fundraisers, speaking at events for those candidates, and using those trips to widen her circle of associations among Democratic activists would be the next thing that I would do," said David Axelrod, who guided Barack Obama to the presidency four years after his election to the Senate.
She is likely to campaign and raise money for candidates who could benefit from her support -- potentially including Ohio Sen. Sherrod Brown -- and to focus on seven House seats in California held by Republicans, but where Hillary Clinton bested Trump in the 2016 election.
"Her greatest focus has been, how can we leverage this moment to build our online following, to help go win the fight in 2018," Clegg said.
"She's leveraging this growth to go fight the most immediate and important battle, which is to defend Senate colleagues and to help those House races."