She tries to blend punch lines with details that build toward a broader narrative. She might shake her head to signal her disapproval while her opponent is speaking, counting on viewers to see her reaction on a split screen. And she has a go-to tactic to pivot debates back in her favor: saying she's glad to answer a question as she gathers her thoughts to explain an evolving position or defend a past one.

Tuesday's presidential debate will put the vice president's skills to a test unlike any she's faced. Harris faces former President Donald Trump, who will participate in his seventh general election debate since 2016, for an event that will be seen by tens of millions of viewers just as early voting in November's election starts around the country.

People who have competed against Harris and prepared her rivals say she brings a series of advantages to the matchup, even as they warn that Trump can be a challenging and unpredictable opponent who veers between policy critiques, personal attacks, and falsehoods or conspiracy theories.

"She can meet the moment," said Marc Short, who led Republican Vice President Mike Pence's debate preparation against Harris in the fall of 2020. "She has shown that in different environments. I would not underestimate that in any way."

Julian Castro, a Democrat who ran for president against Harris in the 2020 primary, said Harris blended "knowledge, poise and the ability to explain things well" to stand out during crowded primary debates.

"Some candidates get too caught up with trying to be catchy, trying to go viral," Castro said. "She's found a very good balance."

Balancing narrative and detail

A former Harris aide, who spoke on condition of anonymity to talk about her approach, said the vice president views the events like a jury trial or querying a judicial nominee on Capitol Hill when she was a U.S. senator. The idea, the former aide said, has always been to win the debate on merit while leaving more casual or piecemeal viewers with key takeaways.

"She understands that debates are about the individual interactions themselves but also about a larger strategy of offering a vision for what your leadership and style looks like," said Tim Hogan, who led Sen. Amy Klobuchar's 2020 primary debate preparation.

Kathleen Hall Jamieson, a political communications professor at the University of Pennsylvania, said Harris makes deductive arguments but folds them into a broader narrative -- the same way she would talk to a jury.

"She states a thesis and then follows with fact, fact, fact," she said.

Jamieson pointed to the 2020 vice presidential debate in which Harris hammered Trump's handling of the COVID-19 pandemic and the economy, and to her most memorable 2019 primary debate when she skewered Biden for how he had talked about race and institutional racism. She weaved her critique of Biden's record with her own biography as a young, biracial student in the early era of school integration.

"That little girl was me," Harris said in a widely circulated quip that punctuated her story about court-ordered busing that helped non-white students attend integrated schools.

"Most people who are good at the deductive argument aren't good at wrapping that with an effective narrative," Jamieson said. "She's good at both."

Landing memorable punches

Castro said Harris has a good feel for when to strike, a quality he traced to her trial experience. In 2019, as multiple Democratic candidates talked over one another, Harris sat back before getting moderators to recognize her.

"Hey, guys, you know what? America does not want to witness a food fight. They want to know how we're going to put food on their table," she said, taking control of the conversation and drawing applause.

When Harris faced Pence in 2020, it was a mostly civil, substantive debate. But she got in digs that framed Pence as a serial interrupter, as Trump had been in his first debate with Biden.

"Mr. Vice President, I'm speaking," she said at one point, with a stern look. At another: "If you don't mind letting me finish, we can have a conversation."

Finding traps in policy

Debates have sometimes put Harris on the defensive.

In the 2020 primary matches, Tulsi Gabbard, who this year has endorsed Trump, blitzed Harris over how aggressively she prosecuted nonviolent drug offenders as a district attorney.

That fall, Pence made Harris sometimes struggle to defend Biden's positions. Now, her task will be to defend not just Biden's record, but her own role in that record and what policies she would pursue as president.

Short, one of Pence's top aides, noted that Republicans and the media have raised questions about more liberal positions Harris took in her 2020 primary campaign, especially on fracking, universal healthcare, reparations for slavery and how to treat migrants who cross the U.S. border illegally.

"We were surprised that she missed some opportunities (against Pence) when the conversation was centered around policy," Short said.

Timing, silence and nonverbal communication

One of Harris' earliest debate triumphs came in 2010 as she ran for California attorney general. Her opponent was asked about his plans to accept his public pension while still being paid a salary for a current public post.

"I earned it," Republican Steve Cooley said of the so-called "double-dipping" practice.

Harris looked on silently, with a slightly amused look as Cooley explained himself. When moderators recognized her, she said just seven words - "Go for it, Steve. You earned it!" -- in a serious tone but with a look that communicated her sarcasm. The exchange landed in her television ads within days.

"Kamala Harris is quite effective at nonverbal communication and knowing when not to speak," Jamieson said.

The professor said Harris often will shake her head and, with other looks, telegraph her disapproval while her opponent is speaking. Then she smiles before retorting, or attacking, in a conversational tone.

"She defuses some of the argument that Trump makes that she is 'a nasty woman,' that she's engaging in egregiously unfair behavior, because her nonverbal presentation is actually undercutting that line of attack," Jamieson said.

Meeting a new challenge with Trump

For all of Harris' debate experience, Tuesday is still a new and massive stage. Democrats who ordinarily tear into Trump instead appeared on Sunday's news shows to make clear that Harris faced a big task ahead.

"It will take almost superhuman focus and discipline to deal with Donald Trump in a debate," said Transportation Secretary Pete Buttigieg, yet another of Harris' 2020 opponents, on CNN. "It's no ordinary proposition, not because Donald Trump is a master of explaining policy ideas and how they're going to make people better off. It's because he's a master of taking any form or format that is on television and turning it into a show that is all about him."

Castro noted that Trump is "a nasty and crafty stage presence" who makes preparation difficult. And with ABC keeping the candidates' microphones off when they are not speaking, Harris may not find it as easy to produce another viral moment that hinges on viewers having seen or heard Trump at his most outlandish.

"The best thing she can do," Castro said, "is not get distracted by his antics."