Arguing that California voters will belie the predictions of political analysts that legions of them will stay away from the polls, some voting experts say to expect a robust launch of the June 7 primary election, which begins Monday with early voting and millions of ballots being mailed to households across the Golden State.

“Any political consultant who’s going around predicting lower voter turnout in this election is mistaken — and should be fired,” said Kim Alexander, president of the nonpartisan California Voter Foundation. “People are going to see the turnout in California as a test of all the major candidates’ popularity. They want to be counted, on the record.”

Roughly half of the state’s voters — more than two-thirds in some Bay Area counties — choose to vote by mail, and beginning Monday county registrars will begin sending out ballots. Local election offices will also open Monday for walk-in voters.

Just a week ago, California was seen as the state where Donald Trump would be forced to battle for the remaining delegates needed to ensure a victory on the first ballot at the Republican National Convention in July. But now Trump is the GOP’s presumptive nominee after Texas Sen. Ted Cruz and Ohio Gov. John Kasich dropped out following the New York billionaire’s landslide win Tuesday in Indiana.

Suddenly the most intriguing race in California is between Vermont Sen. Bernie Sanders and Hillary Clinton. The former secretary of state is expected to win the Democratic presidential nomination, but she might have to spend a lot of money and time in California to avoid an embarrassing loss to Sanders just weeks before her party’s national convention.

Delegate counts be damned, some election watchers predict Californians will seize their chance to cast a ballot for a celebrity who says out loud exactly what he’s thinking at the moment or for a candidate who would be the first woman to lead this nation. Or for America’s would-be democratic-socialist president, the oldest candidate but the one who is the most popular among young voters.

The centrality of race, class and gender along the presidential campaign trail is highlighted in California by a U.S. Senate contest whose best-polling candidates are two women of color vying to make history: California Attorney General Kamala Harris, who is African-American and Southeast Asian, and Rep. Loretta Sanchez, of Orange County, a Mexican-American.

That race will bring out huge numbers of voters as well, said Melissa Michelson, a political science professor at Menlo College in Atherton.

Voting is about “cementing ourselves,” Michelson said. “And this is one of those historic kinds of elections where voting is a statement of identity.”

Last month, California Secretary of State Alex Padilla said there could be a “major surge in voter turnout” based on elections in other states and surprisingly high online voter registration numbers fueled largely by new sign-ups of Californians 25 and under.

More than 560,000 Californians registered to vote or updated their registration information in the first three months of 2016 — far more than for all of 2014. And those numbers have now reached 850,000, said Alexander of the California Voter Foundation.

But that was before Trump beat down his opponents and Clinton stacked up a hard-to-dispute delegate count against Sanders. That’s when the banter among TV talking heads started to make California once again look irrelevant in the presidential contest.

The pundits, though, might have spoken too soon, some veteran California political observers contend.

“We’re seeing many first-time voters,” Alexander said. And in an ultra-blue state, that includes Republicans who say they finally feel included in politics and will be drawn to the polls to say they got a chance to vote for Trump.

Bay Area counties are increasingly offering a potpourri of early-voting options. Santa Clara County, for example, in the next month will have more places than ever to cast votes to accommodate the new voters, said Registrar of Voters Shannon Bushey.

Starting Monday, Santa Clara County residents can drop off ballots at 50 different sites, including city halls, college campuses, libraries, light-rail stations — even Palo Alto’s Mayfield soccer complex and the Westgate Shopping Center in San Jose.

As part of its new Regional Early Voting program, Contra Costa County’s elections department is setting up six polling places — in addition to the county elections office in downtown Martinez — where any voter registered in Contra Costa can vote. If an Antioch resident works in San Ramon, for instance — or vice versa — that resident can vote at the early voting location closest to either home or work.

Alameda County won’t have early polling at multiple locations for the primary election. But early voting will take place starting Monday at the main Registrar of Voters Office in the basement of the county courthouse in Oakland, county spokesman Guy Ashley said in an email. The courthouse offices will also be open on the two weekends before the election.

New this year in Alameda County will be secure drop-boxes in each of the county’s 14 incorporated cities for vote-by-mail ballots, through the closing of the polls on June 7. There also will be a “Ballot Drop Stop” outside the Oakland courthouse during the two pre-election weekends, Ashley said. Drivers can stay in their vehicles for the drop-off.

May 23 is the deadline to register to vote or switch parties. Independents can vote in the Democratic primary, but not in the GOP primary. So, election officials say, now is the time to get it all sorted out.

“In presidential election years, it sometimes feels like every other state gets a chance to have a say before we do. I mean, Guam voted over the weekend!” said Michelson, the Menlo College political expert.

But now, she said, it’s finally our turn.

“If somebody was going to ask me why should we care that early voting starts Monday,” she said, “I would remind them that this is one of the most exciting elections of our lifetime.”

Contact Karen de Sá at 408-920-5781. Sam Richards contributed to this story.