Gov. Jerry Brown hasn't officially declared he'll run for a historic fourth term - but a number of wealthy donors, including health care interests, casinos, tech executives and Hollywood celebrities, have already placed their bets on his future by making hefty donations toward the 2014 governor's race.

State records show that Brown's campaign picked up $5.3 million in major donations alone - checks of $5,000 or more - from July 1 through Dec. 31. That added substantially to Brown's take from the first half of 2013, when he reported $2.8 million in total contributions and $10 million cash on hand, according to the secretary of state's office.

The major donations came from a diverse group that included several movie studios, actors Robert Downey Jr. and Kirk Douglas, porn king Larry Flynt and an Indian casino whose expansion was christened by Brown in December.

Brown's cash pile dwarfs those of the two Republicans who have announced they will run against him, former Lt. Gov. Abel Maldonado and Assemblyman Tim Donnelly of Twin Peaks (San Bernardino County).

Donnelly raised $83,000 and spent $69,000 in the first half of the year, the secretary of state's office reported. After he officially announced his campaign in November, Donnelly raised another $87,400 from major donors through the end of the year.

Big gifts dry up

Maldonado, who announced in April, raised $94,400 in major donations in the second half of the year, state records show. He had $44,600 cash on hand as of June 30.

In an ominous sign for his campaign's economic well-being, Maldonado's last $5,000-plus contribution came in mid-November. That's when Susan and Howard Groff, owners of Northwest Excavating in the Northridge area of Los Angeles, each gave $27,200 to his campaign.

Dan Newman, an adviser to Brown's campaign, said the huge differences in fundraising suggest that Maldonado and Donnelly "are garnering enough support to be viable candidates for sixth-grade class treasurer, but voters and donors are making it clear they want Jerry Brown to serve another term as governor.''

Ron Nehring, a senior campaign adviser to Maldonado, countered that "everybody knows an incumbent California governor can leverage the power of the office to raise vast sums of money from those who are most dependent on access in Sacramento."

But Brown will need "every dollar he can raise," Nehring said. "In a state with more than 2 million more Democrats than Republicans, his (poll) numbers are anemic. ... The state's economy continues to drag well behind the rest of the country.

"This is a long ballgame," Nehring said, "and the players are just now walking onto the field."

Glitzy party for Brown

Brown's late-year fundraising was fueled by a November fundraiser at the Bel Air home of Walt Disney Studios Chairman Alan Horn and his wife, Cindy, which reportedly raised $2 million.

The benefit, from which press was excluded, drew attendees including former U.S. Sen. Chris Dodd, who now heads the Motion Picture Association of America - a $25,000 donor - as well as record mogul. David Geffen, filmmaker Steven Spielberg and Dreamworks CEO Jeffrey Katzenberg, sources said.

By law, donors can contribute $27,200 toward both the primary and general election campaigns.

Other big entertainment donors to Brown included Fox Group Entertainment ($49,400), Disney Worldwide Services ($26,700), Warner Bros. ($27,200), Flynt Management ($54,400), Sony Pictures Entertainment ($54,400), actors Downey and Douglas ($5,000 each), and basketball legend and Los Angeles Dodgers co-owner Magic Johnson ($54,400).

Casino cash

Major gaming interests that donated to Brown included King's Casino of San Diego County, which gave $49,000, Station Casinos in Las Vegas ($55,400) and the Hawaiian Gardens Casino, which donated $37,500.

That check came just two weeks after the governor personally opened the company's expanded Southern California casino in December and praised its owners for "contributing to the local community."

Health care interests that gave the maximum to Brown included the California Hospital Association ($27,200), HealthNet CEO Jay Gellert ($27,200), the Doctors Company PAC ($54,400), Molina Health Care ($54,400) and Anthem Blue Cross ($27,200).

Tech and electronics donors included Norman Pattiz, head of Launchpad Digital Media, and Chester Pipkin, president and CEO of Belkin International, who each donated $54,400. Genentech gave $15,000, and the advocacy group TechNet donated $10,000.

Unions that wrote major checks to Brown's campaign included those representing plumbers and steamfitters, firefighters, pipe trades, ironworkers and carpenters.

Maldonado donations

The bulk of Maldonado's fundraising came in the second quarter of the year, shortly after he became a candidate. He picked up contributions from major GOP donor Charles Munger Jr. ($27,200), former Los Angeles Mayor Richard Riordan ($5,000), former Lt. Gov. Mike Curb ($5,000), author and analyst David Horowitz ($10,000), and engineering-firm mogul Stephen Bechtel ($27,200).

Since then, the former lieutenant governor has replaced his campaign staff, but his fundraising hasn't picked up.

Donnelly spokeswoman Jennifer Kerns said the Southern California conservative exceeded a $25,000 goal he had set for December, and "had a strong campaign launch out of the gate - exceeding expectations of donors, opinion leaders and the media."

Voters' decisions

Kerns said Donnelly is "just getting started" and intends to be aggressive against Brown. "We look forward to getting the message out in a way that Republicans traditionally have not done," she said.

Nehring, too, insisted that the election is far from over.

"If money alone determined election outcomes, we would be talking about Gov. Meg Whitman's first term - and whenever I visit New York, I would drop by the Steve Forbes Presidential Library," Nehring said. "Those don't exist because voters ultimately make their own choices."

Carla Marinucci is senior political writer for The San Francisco Chronicle. E-mail: cmarinucci@sfchronicle.com Twitter: @cmarinucci