And their national party should be leery of nominating someone who can’t even excite the home state voters.

Especially if the state is the nation’s most populated, one that provides nearly one-fourth of the convention delegates needed to nominate a presidential candidate.

I’m referring here to Vice President Kamala Harris, the Californian who has been constantly mentioned in the news media as a top-tier potential replacement for 80-year-old President Biden if he doesn’t run for reelection next year.

Of course, Biden has signaled he does intend to seek a second term in 2024 and will announce this soon. But that hasn’t stopped speculation about “what if?”

Biden will run and Harris will be on the Democratic ticket again. And regardless of whether the president wins or loses, the 58-year-old Veep will automatically be seen as an early front-runner for the party’s nomination in 2028.

Harris, the daughter of immigrant parents — a father from Jamaica and a mother from India — has the distinction of being several “firsts.” She’s the first woman, the first African American and the first Asian American vice president. Ditto California attorney general. She was the first Black U.S. senator from California. And she was the first person of color to be elected San Francisco district attorney.

She looks good on a resume — elective offices at the local, state and national levels. Harris had a quick, uninterrupted climb up the political ladder.

“There’s a sense that she may have come too far too fast,” says Darry Sragow, a veteran Democratic consultant who publishes the California Target Book, which chronicles state elections.

Maybe too fast to acquire a lot political acumen along the way.

The headline on a recent Washington Post analysis read: “Some Democrats are worried about Harris’ political prospects…. Many party activists are not sure the vice president has shown she is up to winning the top job.”

That concern was justified by a California poll last week. It was bad news for Harris. It showed that she leaves a lot of home state voters cold — and not just Republicans, but many independents who represent 23% of the electorate.

Independents — officially labeled “no party preference” — vote in Democratic presidential primaries in California.

The survey of California registered voters was conducted by the UC Berkeley Institute of Governmental Studies and cosponsored by The Times.

Voters were asked how they would feel about Harris running for president next year if Biden didn’t. Their answer: 59% would not be enthusiastic about it; 37% would be.

Among Democrats, 56% would be enthusiastic, but 63% of independents would not. Black voters were the only major demographic group that expressed enthusiasm.

“Californians never have been that enthusiastic about her presidential ambitions or prospects,” notes Mark DiCamillo, the veteran IGS poll director.

Then-Sen. Harris ran for president four years ago but dropped out before the first primary votes were cast. An IGS poll back then showed that 61% of voters thought she should give it up. In polling leading up to California’s primary, she was running fifth with only single-digit support.

In the poll released last week, voters were asked their impression of Harris. It was so-so: 46% favorable and 46% unfavorable. Among Democrats it was 72% favorable. But independents’ views were 51% unfavorable.

Most significant, impressions of Harris have dropped sharply across the board since she became vice president — by 10 percentage points among all voters, 11 points among Democrats and 16 among independents. Black voters view Harris favorably, but their image of her has fallen by nine points.

Biden’s 2020 voters now look on her less favorably by 15 points.

Meanwhile, Biden’s job rating in California has risen to 57% approval, up 10 points in the last year. So, Harris isn’t being dragged down by her boss.

“Once she became vice president, the image of her went way up,” DiCamillo says. “She was vice president. People in the state were somewhat proud of her. But they really don’t want her as president.”

The pollster says he regards independent voters as guideposts.

“I look at them to see which way the wind is blowing,” DiCamillo says. “And the wind is not blowing at her back. It’s in her face.

“Among those voters, there’s relatively little enthusiasm for her. They’re more negative than positive. That’s an indicator. It’s an ominous sign for her.”

I called Fred Smoller, a political science professor at Chapman University.

“She faces some kind of charisma deficit I don’t understand,” he says.

Sragow puts it this way: “A fair number of people think she doesn’t sound authentic.”

Smoller: “Vice presidents are not supposed to be seen and certainly not heard. They can’t prove themselves to the public.”

I’d argue that Biden has given Harris opportunities to shine.

Harris didn’t shine as a senator, either, because soon after she got to Washington in 2017, she started running for president. Before that, she was a risk-averse attorney general who didn’t stand out.

“In our society, the fact she’s a female tends to be a strike against her,” Smoller says. “And she’s a woman of color.”

But Los Angeles and San Francisco have Black female mayors. Californians had two female senators for years. And Harris was elected to the Senate. California, however, still has not elected a woman or a Black governor.

“Californians have never embraced Kamala Harris as a national candidate,” says Rose Kapolczynski, who was former Sen. Barbara Boxer’s political strategist.

“She’s worse in the polls than Biden because when there’s good news, the president wants to be the one delivering it. She’s not very visible.”

Harris’ future seems to be as Biden’s vice president. And I’d suggest someday she run for president — of some university.