GEOFF BENNETT: Gavin Newsom tapped Laphonza Butler to fill the Senate seat long held by Dianne Feinstein, who died last week.

Butler is the president of EMILY's List.

That's a political action committee that backs pro-choice Democratic women.

She becomes the second Black woman to represent California in the Senate, following Vice President Kamala Harris, who swore her in today.

KAMALA HARRIS, Vice President of the United States: Congratulations, Madam Senator.

SEN. LAPHONZA BUTLER (D-CA): Thank you.

KAMALA HARRIS: Congratulations.

GEOFF BENNETT: Butler's appointment, while interim, heats up the Democratic primary race to permanently fill the seat.

Following this all very closely is Marisa Lagos, who covers California politics for KQED.

Thank you for joining us this evening.

MARISA LAGOS, KQED: Thanks so much for having me.

GEOFF BENNETT: So, Laphonza Butler is also the first member of the LGBTQ community to represent California in the Senate.

Tell us more about her background and how Gavin Newsom ultimately selected her for this highly coveted appointment.

MARISA LAGOS: Right.

Well, so she, as you said, has been running EMILY's List for the last two years.

But, in California, she's most well-known for her role as head of the SEIU labor union.

They represented hundreds of thousands of in-home care workers and nursing home workers, the largest union in the state.

Prior to that job, she had worked for their national organization as an organizer.

But she actually has some experience of her own in campaigns.

She was on Kamala Harris' campaign for president before she dropped out and joined the Biden ticket.

And she did some consulting work around that time as well for Airbnb -- well, consulting work for Uber, and she was in-house briefly for Airbnb, so kind of an interesting spectrum, I would say, a lot of labor experience, but a little tech experience as well.

GEOFF BENNETT: Senator Feinstein famously championed issues such as reducing gun violence, women's reproductive rights, equal protection under the law.

What issues might Senator Butler adopt as her own?

MARISA LAGOS: I mean, I would not expect her to be any more conservative than Senator Feinstein on anything.

In fact, I think she is to her left.

I mean, given her experience working at SEIU, what she told us in 2019 really was born out of what she experienced at home.

Her father fell ill when she was a teenager.

Her mother had to work multiple jobs and take care of him.

So she has been a champion for working people.

And I would expect that to continue.

I think we have a lot of questions about other issues.

Obviously, she's been outspoken about reproductive rights.

But this is the first time she will ever be in elected office -- or appointed office, rather.

And so I think there's a lot of questions about -- in the past, she's always been representing other groups or other clients.

Certainly, she shares a lot of those same opinions, but I think we don't fully know yet kind of where she will go.

So we will be watching that very closely.

GEOFF BENNETT: And, of course, the big question now is, will she run for reelection?

As I understand it, she is genuinely undecided.

But her decision has the potential to scramble the California Senate race, what with three prominent Democrats already vying for it.

You have got Adam Schiff, Katie Porter, and Barbara Lee.

Tell us more about that.

MARISA LAGOS: Yes.

And, I mean, this has been a big kind of behind-the-scenes tug-of-war.

Barbara Lee had really lobbied hard and her allies, including the Congressional Black Caucus, to get her appointed to Feinstein's seat.

The governor, Governor Newsom, had promised he would appoint a Black woman if Senator Feinstein didn't finish her term.

And so I do think this just adds a ton of uncertainty for all the candidates, and certainly for now Senator Butler.

She will have to decide quickly.

The primary on Super Tuesday here is less than five months away.

We are a big state with 40 million people.

You cannot just do retail politics here.

And she's not a known quantity to most voters.

That all said, she has got an excellent group of consultants behind her, the same ones that got Gavin Newsom and Kamala Harris elected here in California that she worked for before.

And she has a fund-raising network from her time at EMILY's List.

So, if she runs, she will be formidable.

GEOFF BENNETT: Marisa Lagos with KQED, thanks so much for sharing your reporting with us.

MARISA LAGOS: Thanks, Geoff.

My pleasure.