Sara Nichols is torn.

The environmental activist and political fundraiser loves the three Democratic members of Congress running to replace Sen. Dianne Feinstein — who at 90 has said she will not run for reelection. Feinstein’s wannabe successors all excite Nichols — with their interests in consumer protection, environmental justice and inequality.

“I would be thrilled to see any one of these exceptional candidates win Dianne Feinstein’s seat: Rep. Adam Schiff, Rep. Katie Porter and Rep. Barbara Lee. Sadly, they will be duking it out for the foreseeable future, trying to win our hearts and minds,” Nichols wrote in an April email to her political network.

But as Nichols has thought more about which candidate to support, having a woman represent California in the Senate has become a priority. She also wants generational change, and can’t get past Lee being nearly 77 years old.

Lee “aligns with my political worldview. She’s one of the kindest people I know. I love that woman to the moon and back. But I also love my country, and I love my granddaughter more,” Nichols told The Times.

“My generation has screwed up this planet so badly. We’ve had our chance. Time to move on,” she continued. “The end of her term, though, if [Lee] were to win, she’d be 84. And I had lots of reliable people tell me in 2018 that Dianne Feinstein was showing serious signs of dementia.”

Nichols’ views reflect an anxiety heard among nearly a dozen political activists, donors and elected officials who spoke to The Times and questioned whether it would be right for someone in her late 70s to replace a 90-year-old. Some, like Nichols — who is 76 herself — said a changing of the guard is sorely needed.

If Lee were to win the 2024 Senate race, it could leave the party in the same predicament it faced in 2018, when Feinstein insisted on running again despite calls for her to step aside. She won, but was spurned by the California Democratic Party, which endorsed Kevin de León, then a liberal state senator.

Age remains a sensitive subject, at least publicly, among California’s political glitterati. When Feinstein announced earlier this year that she wouldn’t seek another term, it appeared to clear the path for a younger person to take over.

Porter, a third-term congresswoman from Irvine, is 49. Schiff is 63 and was first elected in 2000. Dodgers great Steve Garvey, 74, is contemplating a run as a Republican. Lee would be 78 on her first day in office if elected. She would join a body where the median age of a senator is about 65, according to the Pew Research Center.

The collective agita over the question only increased during Feinstein’s months-long absence from Washington when she was ill with shingles, and upon her return when, during a discussion with reporters, she appeared to not realize she’d been away from the Capitol.

During this period, Porter, Schiff and Lee would only say they wished Feinstein a speedy recovery and that it was her choice when to hang it up.

Sen. Dianne Feinstein adjusting her sunglasses as she exits the Capitol in a wheelchair.

Sen. Dianne Feinstein, then 89, outside the U.S. Capitol after her return in May. Her months-long absence for shingles only increased concern about her age and her ability to serve.

(Kent Nishimura / Los Angeles Times)

Recent polling from the UC Berkeley Institute of Governmental Studies and The Times indicated that most Californians want Feinstein to resign, and nearly two-thirds of registered voters in the state said her recent battle with shingles showed she was no longer fit to serve.

“How can you say DiFi is old and [Lee] is not,” said one prominent California Democrat, who spoke on condition of anonymity to avoid offending Lee. Others were leery of talking on the record because Feinstein’s failing health has also been such a fraught topic.

“There’s already a frustration about how we’re gonna spend so much freaking money for a safe Democratic seat this cycle — and then what? We have to do it again if she’s not going to be there that long,” the prominent Democrat said.

This all comes at a moment when the two leading candidates to be president of the United States are both over three-quarters of a century old. President Biden, 80, is constantly contending with questions about his age and fitness for office. In a recent ABC News/Washington Post poll, 68% of Americans said Biden is too old for another term as president. In that same poll, 43% said former President Trump, 77, is also too old for another term.

Lee says the questions around her age amount to a distraction — one she addresses head-on but not something that she worries will hold her back. She’s running to win, and despite reports about her only seeking one term, she’s not closing off the option of running again in 2030.

“It’s important for me to stay focused and to not let the noise become a destabilizing factor in my campaign, because I intend to win this,” Lee said. “Voters will make their own decision…. People want representation. The lens that I bring as an African American woman has not been in the Senate for a while, and [there have been] only two African American women since 1789.”

 Side-by-side photos of Reps. Adam Schiff and Katie Porter at work

Democratic Reps. Adam B. Schiff, 63, and Katie Porter, 49, are also running to represent California in the U.S. Senate.

(Kent Nishimura, Robert Gauthier / Los Angeles Times)

At the moment, she’s focused on fundraising. Her campaign advisors say raising $10 million would help propel her into a runoff.

Shortly after the quarterly election fundraising deadline, Lee’s campaign announced she’d raised $1 million in the second quarter and $2.1 million overall. Schiff netted $8.1 million, boosted by headlines around his censure by House Republicans, and has almost $30 million in cash, according to his campaign. Porter has yet to release her numbers.

Lee said donors and supporters bring up her age “only 10% of the time.”

Some of Lee’s allies and other California Democratic Party officials said questions about her age smack of sexism and the same double standard they say Feinstein has faced. Elected officials including former Speaker Nancy Pelosi have repeatedly said that more infirm male senators have served longer with less scrutiny than Feinstein.

“This is the first time I’ve really heard mention of her age. She looks great. I wasn’t even aware that she was 76,” said Los Angeles County Democratic Party Chair Mark Gonzalez, a candidate for state Assembly, who hasn’t endorsed anyone in the U.S. Senate race. “My only pushback to you is: Would you ask a white man that?”

USC Davis School of Gerontology professor Jennifer Ailshire said the focus on Feinstein’s age had become a proxy for frustrations about her being out of step with the Democratic Party’s liberal tilt.

She said the way Lee or even Biden campaign offers some insight into their fitness, because “some of these people in their 70s and 80s are just amazing in the amount of energy they have.”

Lee has been crisscrossing the state fundraising and meeting voters, and just last week she held a multi-stop bus tour through the Central Valley.

“Campaigning is difficult. It’s cognitively challenging. It’s certainly physically challenging. If someone seems to have high energy, they’re probably in pretty good shape,” Ailshire said.

“Health risks do increase with age, and things can always happen to people. That’s a decision that we’re all making when we go to the polls,” she said. “But ultimately, I think if a candidate looks kind of worn down, I might question them a little bit. Focusing on the level of energy that the person is showing can tell us a lot about what the next few years are going to be like for them.”

There are ample examples of Californians supporting older candidates for prominent elected offices. Jerry Brown was elected to his final term as governor at 76, nearly 40 years after he first served in the role. The longtime politician would challenge reporters to pushup contests, and recently told Politico that at 85 he is still fit enough to be president, but that “we’re not like the old Soviet Union, where they had all those men in the Politburo, people want some fresher faces.”

Sen. Bernie Sanders, now 81, won the state’s Democratic presidential primary in 2020. Nearly half a century ago, Californians elected Republican S.I. Hayakawa, a former president of San Francisco State, to the U.S. Senate at the age of 70. And in November, Democrat Shirley Weber, 74, became the first Black politician to be elected as California secretary of state.

Many of Lee’s supporters see her long track record of advocating for progressive policies as a strength. They are captivated by her experience in government representing the most progressive wing of the Democratic Party — and her dissenting views on committing American troops abroad.

The Oakland politician regularly talks about her past: her key role in desegregating the cheerleading team while attending San Fernando Valley High School, her experience getting an illegal abortion in Mexico, her volunteer work with the Black Panthers, and how her career in politics began when she worked on Shirley Chisholm’s presidential campaign in 1972.

One of Lee’s strengths is the wisdom she has attained with age, her supporters say. She has also witnessed this nation’s ever-changing political climate for more than half a century, from Martin Luther King Jr. and the civil rights era to Trump and his right-wing MAGA movement.

Rep. Ro Khanna, a chair of Lee’s campaign, said he was drawn to her willingness to buck convention and take bold stands. The Fremont Democrat was one of the loudest voices this spring calling on Feinstein to step down after she missed an extended period of time. He said that voters saw the senator as someone unfit to fulfill her duties and that it showed how “D.C. politicians get to live by a different set of rules than most Americans who have jobs. There is such a frustration with a political system where entrenched politicians have clung to power for the last 40 years.”

Lee is “fresher than the other candidates. It’s not about age,” Khanna said.

“It’s a willingness to call into question the status quo and be the only vote against a 20-year-war in Afghanistan, be the voice that speaks up against [invading] Iraq, and is a voice that is speaking out against bloated military budgets,” he continued. “When people say ‘Barbara Lee speaks for me,’ that’s what they’re talking about.”

Rep. Barbara Lee walking with other lawmakers

Rep. Barbara Lee leaves a Capitol news conference in May with Reps. Alexandria Ocasio-Cortez, Greg Casar other members of the Congressional Progressive Caucus.

(Kent Nishimura / Los Angeles Times)

Nathan Barankin, a consultant for an independent expenditure committee supporting Lee, said her biggest challenge isn’t age, but introducing herself to voters.

Public and private polling show she’s far less known than Porter or Schiff, he said, adding that there was a wide gulf between voters and political pundits when it came to views on Lee’s age. For voters, he said, being older isn’t a turnoff on its own. Rather, “it’s age plus something — an inability to do the job [or] a misalignment between where Democratic voters are on policy and where the elected is.”

“Advocates for those running who are not named Barbara Lee whisper about this all over the place, and that’s sad to me,” he said.

This spring, Barankin showed poll respondents the campaign launch videos for Schiff, Porter and Lee. Lee’s featured images spanning decades, including a black-and-white photo of her as the first Black cheerleader at her high school.

He said that in polling before voters saw the videos, the numbers were very similar to those in public polls, with Lee trailing Porter and Schiff. But after voters saw the videos, their support for Lee grew — particularly among those 18 to 49 years old, whose support for her tripled. A similar phenomenon occurred among progressive and liberal voters.

“It says that age has no effect unless there is something more,” Barankin said, adding that Lee “has none of the downsides of some of these other candidates — and certainly of Dianne Feinstein — and all of the upsides.”

Former Times staff writer Melanie Mason contributed to this report.