There’s one unmistakable conclusion after 14 presidential candidates stormed through San Francisco for the California Democratic Party convention that ended Sunday: The nation’s largest primary state is up for grabs — and the field of top contenders just got wider.

Some of the Democrats at the three-day event said Massachusetts Sen. Elizabeth Warren had vaulted into the top tier of candidates for the March 3 California primary. She drew several thousand people to a rally Friday in Oakland — Sen. Kamala Harris’ hometown — and delivered a fiery, well-received speech to the convention.

Many around the Moscone Center said Warren belonged with Harris, Vermont Sen. Bernie Sanders and former Vice President Joe Biden as the early leaders vying for California’s nearly 500 delegates to the party’s national convention.

“She had a crisp, energetic message with a clear enemy: billionaires and corporations,” said California Democratic strategist Rose Kapolczynski, who is not affiliated with any campaigns. “And, as she likes to say, she has a plan for how to change things.”

“I was totally shocked by Elizabeth Warren,” said Democratic Assemblywoman Lorena Gonzalez of San Diego, who has not endorsed a candidate. “She was on fire here. It was incredible.”

But if Warren is among the early favorites, the keyword is “early.” Convention delegates tend to be committed activists, but many of those interviewed said they hadn’t made up their minds whom to support and are still shopping.

“There are things that I like about all of them, so I’m still really on the fence,” said Alexia Worscham, 58, a nonprofit worker from Los Gatos. “I hear one of them speak and I think, ‘I like her.’ And then I hear the next one speak. So yeah, I’m really looking forward to the debates and hearing more from all of them.”

Debbie Lima, 65, a retiree from Orange County, said Harris and Warren were her two favorite candidates, with the Massachusetts senator holding a small lead — for now. “Ask me tomorrow,” she joked.

Here are some other takeaways from the convention:

Should Joe Biden have shown up? Biden, who is leading the primary polls both nationally and in California, passed up the convention, and Sanders let him know about it, mocking “those who have chosen for whatever reason, not to be in this room. ... We cannot go back to the old ways — we have got to go forward with a new and progressive agenda.”

“I am disappointed that Joe Biden’s not here,” Gonzalez said. “That’s nice that you’re the front-runner, but don’t sleep on the competition here.”

Robbie Hunter, president of the State Building and Construction Trades Council of California, met with several campaigns this weekend and isn’t ready to endorse anyone, including Biden, who has been courting labor assiduously. But he added, “Our people are not hearing anything out of (Biden) that pertains to their lives.”

Biden, however, could point to his presence Saturday night at an LGBTQ Pride event in Columbus, Ohio, as evidence he was hardly hiding from a Democratic constituency. He also sent word that he’d be coming to California soon — when he won’t be jostling with more than a dozen rivals running behind him in the polls.

Harris defends her turf: Harris, who is polling third in California, had simple goals this weekend: Show strength at the convention and recruit volunteers not just for the California primary but to travel to Nevada for that state’s February caucuses. Volunteers sporting Harris signs and T-shirts were everywhere, and they were loud.

Pelosi unscathed: House Speaker Nancy Pelosi avoided the national political headache that would have resulted had impeachment-loving delegates booed her in her home city. Instead, they just shouted for impeachment, but applauded her speech.

Pelosi also was fortunate that billionaire impeachment activist Tom Steyer didn’t get to the subject of impeaching President Trump quickly enough in his speech to the convention. When he finally arrived at the point, his remarks were drowned out by your-time-is-up music.

Castro’s move: Keep an eye out for the until-now sleepy campaign of former Housing and Urban Development Secretary Julián Castro. He rolled out a new policy proposal Saturday calling for a national standard on when police can use lethal force — an issue that resonates loudly with the Democratic base. He will also introduce a proposal on housing, a subject that has received little attention in the presidential campaign so far.

Castro needs something to jump-start his campaign. He’s the only Latino in the race, but even among Latino voters in California, he’s polling in the low single digits.

When booing might help: Former Colorado Gov. John Hickenlooper is cultivating a centrist position in the 24-candidate field. So he wasn’t embarrassed when the delegates booed at his line, “If we want to beat Donald Trump and achieve big progressive goals, socialism is not the answer.” For good measure, he took a dig at the idea of the government running the nation’s health care system — a favorite in the progressive convention crowd.

Hickenlooper smiled when asked if he wanted to be booed and laughed at the suggestion that he might turn the moment into a TV ad, though he didn’t rule it out. “You have to talk to my staff,” he said.

He wasn’t alone in poking the convention’s progressives. Former Maryland Rep. John Delaney was booed Sunday when he said a government-run health care system “will force hospitals across America to close their doors, because Medicare payments alone won’t cover hospitals’ expenses.”

It seems unlikely that Delaney, who is barely registering in polls, will have the cash to produce an ad from the moment. But he was clearly pleased. Afterward, he released a statement that said that although “a few boos aren’t a big deal, making a really bad mistake on health care is. We can’t be dedicated to slogans and must ensure that a real debate happens.”

Chronicle staff writers Tal Kopan and John Wildermuth contributed to this report.

Joe Garofoli and Alexei Koseff are San Francisco Chronicle’s staff writers. Email: jgarofoli@sfchronicle.com, alexei.koseff@sfchronicle.com. Twitter: @joegarofoli @akoseff