What does it take to get a Republican to vote Democrat?

That’s the central question in California’s senate race, some political pundits say, as two Democrats vie to replace retiring Sen. Barbara Boxer (D).

Polls have for months placed California attorney general Kamala Harris in the lead, with Rep. Loretta Sanchez struggling to raise the support she needs – especially from Republicans and independents – to take on Ms. Harris’s statewide name recognition and endorsement from party leadership.

The race is the first time a seat for United States Senate has opened in the state since its election reforms established a "top two" primary in 2011; the top two voter-getters in any primary, regardless of party, advance to the general election.

With Democrats assured of holding the seat and the lopsided nature of the race, many experts have already dismissed it as a snoozer.

But others say the campaign serves as a window into potential cross-partisan dynamics. What happens when voters are forced to choose between candidates from a rival party? There will be takeaways for how California's top two primary works, but the race could also hold lessons beyond the Golden State.

In an era when voters are so strongly polarized that many see the other party as a threat to America's well-being, California's experiment could begin to offer clues about what does – and doesn't – work in breaking down those lines.

“Voters are so polarized. Is there still a possibility to get a voter to cross a party line?” says Mark Baldassare, president and chief executive officer of the Public Policy Institute of California (PPIC), a nonprofit, nonpartisan think tank based in San Francisco. “How does a member of one party differentiate themselves from another, so they can attract independent voters and cross-over votes?”

“This is a great opportunity to see that happening,” he says.

A race to the middle

In an effort to reform rules that allowed political parties to throw combined support behind a preferred candidate, California voters approved the top-two primary system in 2010. The idea was to make it harder for partisan politics to dominate electoral campaigns and give voters “the power to hold politicians truly accountable,” then-Gov. Arnold Schwarzenegger said.

Legislative races during the past four years have borne out the thesis, some say, as – for the most part – Democrat has taken on Democrat in key campaigns.

In 2012, Rep. Brad Sherman clinched a narrow victory over then-Rep. Howard Berman in the race for California’s 30th district – despite Representative Berman receiving the support of both key party figures and the entertainment industry. The same year, veteran Rep. Pete Stark – at the time one of the most outspoken liberals in Congress – lost to the younger and more moderate Eric Swalwell, then a city councilman, in their bid for the state’s 15th district.

And in 2014, newcomer Patty Lopez beat out incumbent Raul Bocanegra during the state Assembly race for the 39th district, which includes parts of the San Fernando Valley.

In those cases, analysts say, the winners had appealed to voters who did not traditionally support Democrats by presenting themselves as the more moderate alternative.

“At the legislative level, it’s worked out as the original sponsors [of the top-two system] intended,” says Dan Schnur, director of the Jesse M. Unruh Institute of Politics at the University of Southern California. “There’s been an influx of centrist and pro-business Democrats. That wouldn’t have occurred under more traditional rules.”

Big state, big money

A similar dynamic has played out between Harris and Representative Sanchez. Harris, the party favorite, is firmly liberal, and has the support of party leadership and President Obama. Sanchez, meanwhile, is more conservative in her fiscal policy and stances on gun rights and national security. Her positions have won her the support of Republican Rep. Darrell Issa. PPIC polls also have Sanchez leading Harris among Latinos.

But with her war chest just short of a million dollars at the end of June, Sanchez has struggled to get her message out to a broader voter base. With Harris already at an advantage in terms of name recognition – she’s appeared on statewide ballots four times before – the lack of cash has further prevented Sanchez from closing the gap.

And there lies the difference between a legislative race and a statewide campaign, political observers say: Top-two system or not, in a state as large and diverse as California, funding is key.

“You need big money to get your name out there,” says Mark DiCamillo, director of the nonpartisan Field Poll.

The victors in previous legislative races “prevailed because they made it clear to voters from the non-represented party why they were the preferred candidate,” says Professor Schnur. “Sanchez simply hasn’t had the resources to let that be known.”

And it shows: Nearly 70 percent of Republicans say they either won’t vote in the Senate race this year or are undecided, according to the Field Poll. Forty-four percent of independents say the same. According to the PPIC, the figures are at 62 percent for Republicans and 45 percent among independents.

Lessons emerging

A better grasp of how to run a campaign against a fellow party member could be crucial in future races, political analysts say – especially in California where the odds are that the 2018 gubernatorial race will see two Democrats vying for Jerry Brown’s seat.

“What you see here is something you’re going to see in more races,” says Raphael Sonenshein, executive director of the Pat Brown Institute for Public Affairs at California State University, Los Angeles. “Different communities will be striving for attention statewide … and sooner or later Republicans and independents will give recognition to candidates who can appeal to a broader base of California voters.”

The implications could extend beyond the state, as well, some say. The US political scene continues to grow more polarized: the share of Americans who express consistently conservative or liberal views has more than doubled in the past two decades, the Pew Research Center reported in 2014.

At the same time, more Americans are refusing to register with a party, with about 40 percent identifying as unaffiliated in 2014, according to Pew.

Get the Monitor Stories you care about delivered to your inbox. By signing up, you agree to our Privacy Policy

As such, knowing the kind of resources and messaging required to clinch cross-over votes and win over nonpartisan voters is increasingly important to politicians across the country, pundits say.

“There’s a lot of interest in that beyond California,” Mr. Baldassare at PPIC says. “Whatever can be learned here could be applied to how to reach out to voters who are independents and Republicans so that they will feel there is a possibility of being represented by somebody who belongs to a party that is different from their own.”