Harris’ whirlwind running mate search enters final hours as she prepares to take new Democratic ticket on the road

(CNN) — Vice President Kamala Harris is making the biggest decision of her two-week-old presidential campaign as she chooses a running mate and prepares to introduce the new Democratic ticket to voters in several key battleground states this week.

Harris is focusing on Pennsylvania Gov. Josh Shapiro and Minnesota Gov. Tim Walz, multiple sources familiar with the matter told CNN, although the process, these sources cautioned, is still fluid and none of the finalists can be ruled out until Harris makes her decision. Arizona Sen. Mark Kelly remained in the running as of Monday afternoon, a source told CNN.

The selection will kick off a new phase of the campaign, as Harris seeks to maintain the momentum that has propelled her bid and former President Donald Trump struggles to adapt to running against an entirely new candidate.

The decision is expected to be made later Monday, and once it is made, the vice president would inform a small team of top advisers and her pick. Sources cautioned, however, that the decision is ultimately Harris’ to make – and if she needed more time, the final decision could slide into Tuesday.

The campaign plans to officially announce the choice through an online message to supporters before a rally in Philadelphia on Tuesday, where she’s expected to make her first appearance with her pick. Harris hopes to keep it under wraps “until as close to then as possible,” a person familiar with the search told CNN.

The whirlwind vice presidential search entered its final hours Sunday after Harris had interviewed three final contenders — Walz, Shapiro and Kelly — and weighed her choice with advisers out of public view for three straight days.

An extraordinary campaign for and against the candidates broke out across the spectrum of the Democratic Party last week and over the weekend. Different stakeholders have made their own arguments about who would be most electable against Trump — and who could help Harris sustain the streak of positive news her campaign has been riding for the past two weeks, while the former president has been put on the defensive over his own vice-presidential pick, Ohio Sen. JD Vance.

Since President Joe Biden ended his reelection bid last month and endorsed Harris, the vice president has locked up the support of the Democratic Party and improved on the president’s polling against Trump. A new CBS News/YouGov poll released Sunday, for example, found no clear leader between Harris and Trump among likely voters nationally — whereas Biden had been down 5 points in previous CBS News/YouGov polling. A CNN average of four recent polls also found a close matchup between the two, with Trump averaging the support of 49% and Harris averaging 47%.

Harris’ candidacy has energized Democrats and stirred donors, with her campaign announcing last week that it had raised $310 million in July, more than double Trump’s haul of $138.7 million. And on Friday, the Democratic National Committee announced that Harris had won enough delegate support to win the party’s nomination ahead of the end of the voting period Monday.

It was four years ago this week that Biden announced his decision to choose Harris as his running mate. He did so on August 11, 2020, through a text message and email to his supporters. Harris is hoping to make her choice known in the same manner, aides said, in hopes of building anticipation and a massive campaign list.

“I want you to be the first to know who I am selecting to serve alongside me as Vice President,” Harris wrote in a campaign email last week to supporters. “Add your name to this exclusive list of supporters who will be notified immediately when the news breaks.”

Her running mate selection will also help shape the ticket at a time when Harris has been trying to moderate her image with voters since her short-lived presidential campaign in 2019. Last week, her campaign clarified her position on a number of issues, including that she no longer supports “Medicare for All” or a ban on fracking. And on Sunday, Republicans for Biden relaunched in support of Harris — as the vice president’s team hopes to win over Republicans who oppose Trump and independents and make clear that she is not a “San Francisco radical.”

As the running mate selection process drew to a close, observers made their case for different contenders on the Sunday shows.

“I think she needs to pick someone who’s more moderate than her. I think she needs to pick someone that’s got more governing experience at the ground level,” former New Jersey Republican Gov. Chris Christie said on ABC News’ “This Week.”

“It should be Josh Shapiro, I don’t think this is a hard choice,” the one-time Trump ally said.

United Auto Workers President Shawn Fain, whose union endorsed Harris, said he favors Kentucky Gov. Andy Beshear, praising him as a labor ally who was able to win a red state twice, and also approves of Walz.

“Those would be our top two if we had to pick any, but ultimately, look, Vice President Harris has to pick who she’s most comfortable with because it’s her running mate,” Fain said on CBS News’ “Face the Nation.”

Trump confronts a new campaign

While Harris has been preparing to choose a running mate, the Trump campaign has struggled over how to reshape the narrative around her.

Despite his campaign’s efforts to paint Harris as “dangerously liberal,” the former president attacked Harris’ racial identity, saying she “happened to turn Black” during a panel interview at the National Association of Black Journalists convention last week.

Republicans have urged Trump to focus on policy, not race or identity.

“Every day we’re talking about her heritage and not her terrible, dangerous liberal record throughout her entire political life, is a good day for her and a bad day for us,” Sen. Lindsey Graham, a South Carolina Republican and Trump ally, said on “Fox News Sunday.”

“I would encourage President Trump to prosecute the case against Kamala Harris’s bad judgment.”

During a Saturday rally in Atlanta, where Harris had addressed supporters days earlier, Trump sought to blunt some of the momentum she has enjoyed since launching her campaign, while defending Vance, who’s faced scrutiny over past controversial comments.

“We have to work hard to define her,” Trump said. “I don’t even want to define her. I just want to say who she is. She’s a horror show.”

But he also took the opportunity to lash out at a fellow Republican in the key battleground state, disparaging Gov. Brian Kemp, who revealed last month that he did not support Trump in the state’s GOP primary. (The governor has said he’ll “support the ticket” in November.) Earlier in the day, Trump attacked Kemp and his wife on Truth Social.

The rally followed hours of the Trump and Harris campaigns engaging in a public back-and-forth over when they would meet on the debate stage after the former president said he would no longer attend a September 10 ABC News debate he agreed to when Biden was still the nominee.

After two weeks of sowing doubt over whether he would attend, Trump said Saturday he would instead meet Harris at a September 4 Fox News debate with a live audience or not at all.

“We’re doing one with Fox, if she shows up,” Trump said. “I don’t think she’s going to show up,” he added.

Harris’ campaign has said she will attend the ABC News event, and taunted the former president for backing out of that event.

“It’s interesting how ‘any time, any place’ becomes ‘one specific time, one specific safe space,’” Harris wrote on X Saturday. “I’ll be there on September 10th, like he agreed to. I hope to see him there.”