(CNN) When an animal rights protester leapt on stage Saturday to confront Kamala Harris , one of the people who rushed onstage to grab him was her husband Doug Emhoff—a man unknown to most voters, but who is a constant presence at her side on the campaign trail.

By the time Emhoff confronted the protester in a man-bun who was addressing the crowd with the microphone he'd grabbed from Harris , the California senator had already calmly walked off stage; and Karine Jean-Pierre, the co-moderator of the MoveOn forum who is also the chief public affairs officer of the organization and a veteran political operative, had stepped in between the protester and Harris to de-escalate the situation that occurred midway through the MoveOn forum in San Francisco.

But it was hard to miss Emhoff's outraged scowl as he and several other men hustled the man off stage, as Emhoffreached in to wrestle his wife's microphone out of the protester's hand.

It was a protective gesture by Emhoff, an attorney with DLA Piper who identifies himself on Twitter as a "dad, @kamalaharris hubby/stan, lawyer" and "wannabe golfer." The sight of a husband rushing to defend his wife was a relatable, but also complex, moment for the female candidate, who has defined herself as a fierce potential adversary for President Donald Trump -- one who needs no protection.

The courtroom versus the campaign trail

Until the Saturday incident, the Brooklyn-born Emhoff had been a quietly supportive presence who was often spotted backstage or at the edge of Harris' crowds at both her campaign events and book tour events this year.

Unlike other candidates — like South Bend, Indiana, Mayor Pete Buttigieg, who frequently talks about his relationship with his husband Chasten on the trail and has delegated speaking roles to him at several public events — Harris has stuck to a few anecdotes about their courtship and their family, preferring, for the most part, to keep her private life private.

Though Emhoff has shied away from the spotlight, he did a rare interview in March with The Hollywood Reporter where he discussed his work in entertainment litigation.

Emhoff told the trade publication that he has enjoyed continuing to practice law as a refuge in the midst of the campaign "because it's something that I love and I'm good at."

The Brooklyn native, who moved to Southern California in his teens and attended the USC Gould School of Law, launched his own firm in 2000 before Venable acquired it in 2006. At DLA Piper, Emhoff has continued to focus on business, entertainment and intellectual property law in both California and Washington, DC.

Single for many years as she focused on her career as a prosecutor and District Attorney of San Francisco, Harris opened up about Emhoff for the first time in her memoir "The Truths We Hold: An American Journey," which was published this year.

The courtship

The couple was set up on a blind date in 2013 when Harris was California's attorney general by her best friend, Chrisette Hudlin, who announced to Harris over the phone one day that she was going on a date with Emhoff; there was no sense arguing; and forced her reluctant friend to promise not to "Google him" or "overthink it."

Harris acknowledged in her book that, for years, "dating wasn't easy" as a single woman in her 40s at the top of her profession. She knew if she brought a man to an event, people would immediately begin speculating about her private life.

"I had no interest in inviting that kind of scrutiny unless I was close to sure I'd found 'the One,'" she writes in "The Truths we Hold."

Emhoff was divorced with two children that he and his first wife Kerstin named after John Coltrane and Ella Fitzgerald.

Harris writes that she and Emhoff hit it off from their first phone conversation "cracking each other up, joking and laughing at ourselves and with each other, just the way we do now." Harris was drawn to the fact that he was "genuinely comfortable with himself."

He emailed her the morning after their first date outlining his available dates for the next couple of months and telling her he was "too old to play games or hide the ball" because he really liked her.

With some trepidation as a child of divorce — who did not want to intrude too quickly into the lives of her boyfriend's children — Harris waited for several months to meet Cole and Ella, who were in high school and middle school, respectively, at the time.

Trading her trademark suit for jeans and her Chuck Taylors, the California senator has spoken openly about her nervousness about that first meeting and her relief when Cole and Ella ultimately welcomed her into the family with the nickname "Momala."

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"I was determined not to insert myself in their lives until Doug and I had established we were in this for the long haul. Children need consistency; I didn't want to insert myself into their lives as a temporary fixture because I didn't want to disappoint them. There's nothing worse than disappointing a child," Harris wrote in a piece in Elle Magazine on Mother's Day. She forged a friendship with Ella and Cole's mother, Kerstin, who she describes as an incredible mother.

After their swift courtship, Doug proposed in 2014 during a discussion of what kind of Thai take-out to order. The couple was married at the courthouse in Santa Barbara later that year in a ceremony officiated by Harris' sister Maya.

"We sometimes joke that our modern family is almost a little too functional," Harris wrote in Elle in May . "Our time as a family is Sunday dinner. We come together, all of us around the table, and over time we've fallen into our roles. Cole sets the table and picks the music, Ella makes beautiful desserts, Doug acts as my sous-chef, and I cook."

Reacting to their ups and downs of the 2016 election

In the beginning, it was so rare for Harris to introduce a boyfriend into her public life that she noticed her staffers whispering to each other — wondering who Emhoff was — at the first event he attended, which was one of her speeches about truancy at the California Endowment.

Beyond joking about how attractive Emhoff looks in his "onion goggles" in the kitchen, the one anecdote about Emhoff that Harris tells most often on the campaign trail, is about their joint shock on Election Night in 2016 when Hillary Clinton lost to Trump.

She notes at the beginning of her memoir that Emhoff wakes up before her most mornings and reads the news in bed: "If I hear him making noises—a sigh, a groan, a gasp—I know what kind of day it's going to be."

On election night in November of 2016 when she was elected to her first term in the US Senate and Clinton lost to Trump, Emhoff's groans while monitoring the early election results were Harris' first hint that things were going south for Clinton.

After Harris' speech, which she frequently describes as a "bittersweet moment," she and Emhoff went home with their extended family, changed into sweats and watched the results come in from the living room.

"No one really knew what to say or do," Harris writes of her election night blues. "I sat down on the couch with Doug and ate an entire family-size bag of classic Doritos."

The life of a campaign spouse

Emhoff has not said what his role would be if Harris succeeds in her quest to win the White House—or whether he'll continue practicing law.

For now, he's still getting used to doing "Dougie selfies" on the trail. And he's provided Harris fans with a steady stream of behind-the-scenes photographs from the trail, including a snapshot Saturday when he and Harris rivals Beto O'Rourke and Amy Klobuchar chatted at the SEIU forum in California.

But even before Saturday, his public profile was slowly rising. He will be one of the featured speakers at the Florida Democratic Party Gala next weekend at Disney's Yacht & Beach Club.

On Twitter, he called out for advice from "the #KHive, the #DougHive and @KamalaHarris world" for "a good 'walking out' song" to warm up the Florida crowd.

After the MoveOn forum incident, he acknowledged the flood of tweets from well-wishers—some of which included some zoomed-in screengrabs of his scowl while confronting the protester—about his husband-spidey moves with a picture of himself and his wife, and two red hearts.

"Thx for all the kind notes. We are good," Emhoff tweeted. "I love @KamalaHarris and would do anything for her."

This story has been updated.

CORRECTION: This story has been updated to correctly identify Karine Jean-Pierre as the Chief Public Affairs Officer of MoveOn.