Joe Biden had a message for Sen. Kamala Harris at one of his recent virtual fundraisers: "I'm coming for you, kid."
Harris, once an archrival of Biden's during the Democratic primary race, was a special guest to that event and has become one of the early favorites to be chosen as the former vice president's running mate against Donald Trump.
Harris and another former contender, Sen. Amy Klobuchar, have been working behind the scenes to help Biden overtake Trump in a campaign that has been forced to go virtual because of the coronavirus pandemic. The two separately endorsed Biden after they dropped out of the race and have since been in legislative efforts to ease the effects of the coronavirus.
Their work on behalf of Biden includes voter outreach and virtual fundraising events. They are also looking to make an appearance on Biden's podcast and are trying to help Democrats making runs for the GOP-controlled Senate, their campaign aides told CNBC. These advisors were granted anonymity in order to speak freely about how Harris and Klobuchar are trying to assist Biden in the wake of Sen. Bernie Sanders' departure from the presidential race last week.
Biden has said he's been working with his team to whittle down a list of potential vice presidential choices and is putting together a committee that would be responsible for the vetting. Betting markets say Harris is the favorite over Klobuchar and Michigan Gov. Gretchen Whitmer, who has become a star in the Democratic Party by leading her state's response to the coronavirus.
Biden previously told MSNBC that Whitmer is on his list of possible VP picks and has not officially named anyone.
Trump has found a way to remain in the national spotlight, despite his administration being criticized for its handling of Covid-19. Trump's campaign and the Republican National Committee announced on Monday that they combined to raise more than $63 million in March alone and have $240 million on hand.
Biden has been trying to stay on voters' minds by showing how he would handle things differently if he were in charge, making the Harris and Klobuchar efforts to assist him even more imperative. While he has yet to announce his March fundraising totals, having Harris and Klobuchar donors aligned with him could be a crucial boost for his campaign.
Biden's allies in the business community have been pushing his team to look at these three women, plus Sen. Catherine Cortez Masto of Nevada and Rep. Val Demings of Florida.
A Wall Street executive backing Biden, who spoke on condition of anonymity in order to speak freely about the situation, told CNBC late last week that, along with Harris and Klobuchar, he believes New Mexico Gov. Michelle Lujan and Sen. Elizabeth Warren will be on the VP list.
"I think it will be a decision between whether he will make a geographic choice, will it come down to what's going on in the Midwest, for example, or doing something with Harris where it becomes more of a national campaign," the executive said.
Still, the two former primary opponents of Biden have been using their resources to help the Democrats retake the White House and make inroads in Congress.
Klobuchar has been helping the Biden campaign raise money through telephone calls and plans to participate in virtual fundraising events and his digital town halls, one of her aides said. There are also plans in the works for the Minnesota Democrat to join Biden's new podcast, a platform that has already features Whitmer.
Klobuchar is looking to conduct "direct voter contact" in regions of the country Biden will need to overcome Trump in November, especially the Midwest, the aide said. Targeted states will include Minnesota, Pennsylvania, Michigan and Wisconsin, plus women, seniors, rural and suburban voters.
Klobuchar said in a recent SiriusXM interview that she has yet to speak with Biden about her becoming his VP and that she's primarily focused on voting rights during the coronavirus outbreak.
Harris is likely not done taking part in virtual fundraisers for Biden and will get back on the campaign trail advocating for Biden in person once her home state of California fully lifts its stay-at-home order, an aide said. She's been a vocal critic of Trump's handling of the coronavirus.
She is also putting much of her political clout into helping Democratic Senate candidates win in 2020.
Harris recently started a "Meet the Candidates" series in which she touts various Senate candidates and the reason voters should back them over their Republican counterparts. Her first episode was on Thursday with Jaime Harrison, a Senate candidate in South Carolina taking on Sen. Lindsey Graham. Cook Political Report recently predicted a likely Graham victory.
In the episode said Harris talked about how Harrison lives by his values and why someone like him is needed in the Senate. "He is someone that believes all publicly elected officials should give back, and [Harris] highlighted Harrison Helps," one of her aides told CNBC in describing the discussion with voters. "Harrison Helps" is a volunteer organization that focuses on service projects around South Carolina, his website says.
Many more events featuring other Senate candidates are planned for the series, although the aide would not say who's up next. Harris could be targeting states where Democrats are considered to have a shot at winning Senate seats, such as Arizona, Colorado, Maine and North Carolina.
Another decision Harris has made is to start a joint fundraising operation with the Democratic National Committee, a move that often is reserved for candidates running in national elections. Biden and the DNC have started to lay the groundwork for a joint fundraising committee.
Harris' allies with knowledge of her efforts believe the efforts are intended to help Biden break through the near-lock of media attention by Trump, governors and members of Congress because of the pandemic, especially after Sanders dropped out of the presidential race.
"With the benefit of Bernie standing down, Kamala has recognized there needs to be an all-hands-on-deck effort to help the VP breakthrough the noise and raise money, given that Covid issues are going to be with us through the fall to some degree," one of Harris' top financiers told CNBC, speaking on condition of anonymity in order to speak openly.
A spokesman for Biden did not return a request for comment.