What will it take to win a US Senate seat in California?

When Barbara Boxer first ran for the Senate in 1992, she spent $10 million dollars. In her most recent race four years ago, she spent more than three times that amount: $32 million.

That 2010 contest was the first wave of Senate races in the post-Citizens United world: Free of spending limits outside groups spent an additional $21 million.

With Boxer retiring in 2016, it will be the first open U.S. Senate seat in nearly a quarter of a century. Marc Sandelow, who teaches political science at the University of California's Washington Center says if it's a competitive race, "this will be the most expensive race in the history of American politics."

The current spending record was the 2014 Senate race in North Carolina - $118 million. 

But money alone doesn’t guarantee a win at the polls. Democratic strategist Darry Sragow says the political landscape in the Golden State "is littered with the bodies of very wealthy people who decided that they would run for office and didn’t make it."

Nearly two dozen wealthy Californians have tried: Former airline executive Al Checci spent $40 million of his own money in 1992, losing to Gray Davis as governor. Michael Huffington spent $30 million trying to unseat Senator Dianne Feinstein. In 2010, Hewlett-Packard and E-Bay executive Meg Whitman kicked in nearly $150 million of her own money, but lost to Jerry Brown. 

Money can help buy name recognition, but it’s not enough. 

In 2010, Carly Fiorina lent her senate campaign a million dollars, but stumbled the day after the primary when she was caught on tape making fun of her opponent, asking “God, what was that hair?  So yesterday."

Every politician in his or her first race tends to make mistakes, says Dan Schnur.  He was media advisor to GOP Governor Pete Wilson and now runs the Institute of Politics at the University of Southern California

"The question is whether you’re going to make those mistakes in a campaign for school board or city council or in a campaign for governor or for United States Senate before an entire state and an entire nation."

There’s another problem for self-funded, wealthy candidates: mistrust. Sragow says he’s heard voters in focus groups say they must be doing this "because they’re bored and they have a giant ego and they think they can buy their way into office."

California has an unusual primary:  The top two finishers face off in November, regardless of party.

Because of the state's registration, it’s generally expected that both of those Senate candidates in November of 2016 will be two Democrats.

But Republican Congressman Darrell Issa says there is a way a Republican could get to the November ballot.

"Under our 'jungle primary' system," he says, "if 15 Democrats run, then inevitably one or maybe even two Republicans could win." 

It happened in 2012 in a heavily Democratic Congressional seat in the Inland Empire. Democrats split the primary vote and a pair of Republicans ended up on the ballot. 

But Marc  Sandelow says it’s more difficult for a GOP candidate to win a statewide race in California. He says it's always possible for a "progressive Republican, with a tremendous media presence and a great deal of their own money, and socially liberal views and a kind of charisma that screams 'I’m not part of Washington.' It’s always possible that that kind of candidate could come along."

The last successful candidate of that stripe: Arnold Schwarzenegger. His politics were progressive, he had plenty of money, and he didn’t have to worry about name recognition.