The competition to replace Gov. Jerry Brown in 2018 has already heated up, with five prominent California Democrats already campaigning or angling to throw their hat in the ring.

Along with Lt. Gov. Gavin Newsom, who sought to get ahead of the pack by leaping in first, and former Los Angeles Mayor Antonio Villaraigosa, a perennial floated candidate for higher office, state treasurer John Chiang and billionaire activist Tom Steyer faced likely competition from former controller and 2006 gubernatorial candidate Steve Westly.

Money and power

With the exception of Chiang, the crop of candidates and plausible candidates have been distinguished by either their wealth, their ambition, or both. Newsom was famously humbled by Gov. Brown, chafing under the marginal role he has had to play in office. “He’s busily raising money and trying to get as much media attention as his powerless office allows,” Dan Walters observed at the Sacramento Bee. Villaraigosa, Walters added, also sidelined over the past several years with a combination of personal and professional criticism, “is trying to maintain a presence by traveling the state on what he describes as an effort to educate himself about its issues.”

Known across the country, at least by Democrats, Tom Steyer has ranked among the biggest money players in party politics. Steyer “has used his political action committee, NextGen Climate Action, to bring climate issues to the forefront of policy discussions,” the Los Angeles Times noted — an approach that succeeded in landing him a spot at last month’s annual House Democratic Caucus meeting.

During the 2014 election cycle, Steyer dumped about $67 million into NextGen — making him “the country’s biggest individual political donor” that year, according to an analysis by Politico. Steyer has asserted that “he expects to spend even more cash in 2016, focusing on his clean energy-focused super PAC that’s been aggressively organizing across the country, especially in Iowa.” His outsized presence could mobilize voters and bring a more independent flavor to the race. On the other hand, some Democrats uncomfortable with the influence of donor money on politics could be turned off.

A glimpse of reform

Those sorts of voters could be drawn toward John Chiang. (Westly, like Steyer, “has considerable personal wealth” from his time as a venture capitalist, as Walters noted. During president Obama’s visit this month, Westly will host “a fundraiser for the Democratic National Committee […] at his Atherton home,” according to the San Jose Mercury News. “Ticket prices range from $250 to $25,000.”) Rather than racing to shoot out of the gate like Newsom, Chiang has slow-walked his decision. “In August, the state treasurer told the Los Angeles Times he was ‘contemplating’ a run for governor,” the Sacramento Bee recalled. “Three months later, Chiang was ‘very interested,’ according to Capitol Weekly. And on Tuesday, at a California Business Roundtable event, Chiang offered this incremental inch forward: ‘I am strongly leaning towards running.'”

The 2016 election, according to the Associated Press, will be “a free-for-all among a new generation of California Democrats.” With the help of California’s Top 2 Primary, California Republicans even have an outside chance of capitalizing on that anticipated Democratic free-for-all. If multiple Democrats split the primary vote, two Republicans could make the runoff and win the seat that’s been held by Boxer for two decades.

That very long-shot nearly happened in the 2014 race for state controller. Democrats Betty Yee and Speaker of the Assembly John Perez nearly lost out to Republicans David Evans and Fresno Mayor Ashley Swearengin. After finishing second to Swearengin in June, Yee ultimately won in November.

Democrats confident in diverse bench

As CalWatchdog.com reported yesterday, “Boxer’s retirement is the beginning of the changing of the guard in state politics.” California Democrats’ oldest guard, party Chairman John Burton, 82, confidently predicted Democrats would hold the seat in 2016.

“As difficult as it is to imagine California without Barbara Boxer looking out for us in the U.S. Senate, we’re confident California Democrats will have plenty to choose from when it comes to electing their next U.S. Senator,” Burton, an old San Francisco liberal, said in a statement.

So, who are those Democrats ready to take over as Boxer’s successor? Possibly the strongest candidate is one of her former staff members, a man who has gone on to have a successful political career in his own right.

Treasurer John Chiang leads field of potential challengers

On paper, State Treasurer John Chiang, who worked for Boxer early in his career, might be the strongest candidate to succeed her in 2016.

“Senator Boxer has been a stalwart champion for environmental, social, and economic justice,” Chiang said in a statement. “It was an honor to work with Senator Boxer, and I wish her the very best.”

Chiang, the son of Taiwanese immigrants, doesn’t get top billing from political insiders, in part, because he’s been willing to buck the Capitol establishment. When state lawmakers failed to pass a balanced budget on time in 2011, Chiang withheld their paychecks, a move that was heralded by the Howard Jarvis Taxpayers Association. As state controller, he also opened up the state’s books by publishing payroll data for hundreds of thousands of public employees.

Those decisive actions have helped Chiang appeal to moderate Republicans and independent voters. It also explains why he received the most votes in the November election after Gov. Jerry Brown. In 2014, Chiang raised more money than either Attorney General Kamala Harris or Lt. Gov. Gavin Newsom, both of whom receive more hype as Boxer’s potential successor.

Do Harris, Newsom have a pact?

The first names mentioned by the inside-the-Beltway crowd, Harris and Newsom, are sending signals that they won’t run against each other for Boxer’s seat. The two constitutional officers, who share political consultants, SCN Strategies, put their unity on full display earlier this week. Newsom was sworn in for his second term as lieutenant governor by “his good friend” Harris.

Of the two, Harris is expected to run for U.S. Senate, giving Newsom a clear path to governor in 2018. That’s subtly reinforced by their campaign websites. There’s no mention of the AG’s office on Harris’ campaign homepage, KamalaHarris.org, while Newsom’s still mentions he’s lieutenant governor.

But Harris could run into trouble in her campaign for U.S. Senate. Although she cruised to reelection in 2014, she had a competitive race in 2010, when she narrowly defeated Los Angeles District Attorney Steve Cooley. After leading in the polls, Cooley plummeted when he publicly admitted that he’d “double dip,” collecting a pension and his paycheck.

Steyer, Villaraigosa also formidable challengers

Former Los Angeles Mayor Antonio Villaraigosa, another strong contender, is sending mixed signals about his interest in the race. Bloomberg’s Jonathan Allen reported the 61-year-old Democrat is “seriously considering” a run.

But according to the Wall Street Journal, “A person close to Mr. Villaraigosa said a Senate campaign was unlikely for the former mayor. ‘The only seat he cares about is running for governor. He has been a legislator and he’s been an executive, and if he wanted to continue his political career, it would only be as an executive,’ the person said.”

Another Democrat playing it coy is billionaire Tom Steyer. In the 2014 midterm elections, Steyer’s Next Gen Climate PAC spent $74 million on liberal candidates. Politico reported last month that liberal activists at a League of Conservation Voters event in New York City were encouraging Steyer to consider a U.S. Senate campaign. “Tom has consistently said that he will consider the best ways to have the biggest impact,” Chris Lehane, Steyer’s political consultant, wrote in an email to Politico.

GOP candidates: Sundheim, Del Beccaro

Among the first Republicans to react to Boxer’s retirement news was San Diego County Republican Party Chairman Tony Krvaric.

“Being a far left Senator, Barbara Boxer never met a tax increase, regulation, or intrusion on personal freedom she didn’t support,” said Krvaric, one of the state’s most successful GOP party leaders. “Californians deserve a Senator who understands the needs of the average citizen — not out-of-touch San Francisco elites.”

That, at least momentarily, signaled the possibility that California’s top Republican official, San Diego Mayor Kevin Faulconer, might be considering the race. However, Faulconer quickly said he wasn’t interested. Other Republicans who’ve thrown cold water on a bid: former California Gov. Arnold Schwarzenegger, former Secretary of State Condoleezza Rice and Rep. Darrell Issa.

That leaves two former chairmen of the California Republican Party as the only Republicans who are exploring bids: Tom Del Beccaro, a Bay Area author and attorney who served as CA GOP chairman from 2011 to 2013; and Duf Sundheim, another Bay Area lawyer who served as party chairman from 2003–2007.

“If I did run, I would run a very different campaign,” Sundheim said in a statement announcing his intent to explore the race. “What I am exploring is whether such a campaign is viable.  My plan is to go around the state, listen to the dreams people have for themselves, their family and their community and then decide.”

Other potential candidates include Democrat Steve Westly, a former California state controller; and Republicans Neel Kashkari, who lost to Brown for governor last year; Meg Whitman, the Hewlett-Packard CEO who lost to Brown in 2010; and House Majority Leader Kevin McCarthy.

According to the Los Angeles Times, unnamed sources close to Facebook COO Sheryl Sandberg, a Democrat, said she isn’t interested in running.