U.S. Sen. Barbara Boxer crashed through a barrier when her election victory nearly a quarter century ago marked the ascent of women in Washington. Her successor could achieve a breakthrough as well, one that reflects California's steadily changing political demographics.
When the California Democrat won her first term in 1992, 8 of 10 voters in that election were white. Far more Hispanics and Asian-Americans call the state home today compared to a generation ago, and her recently announced exit has revealed a diverse field of potential candidates.
The maneuvering showcases the growing influence of minority voters and a challenge for the Republican Party, which has struggled for years to make inroads with many of them.
Attorney General Kamala Harris, the first Democrat to enter the 2016 contest, is the daughter of a black father and an Indian mother. Her possible rivals include prominent Hispanics, such as Los Angeles Mayor Antonio Villaraigosa and Reps. Loretta Sanchez and Xavier Becerra, and state Treasurer John Chiang, whose parents came to the U.S. from Taiwan.
"It's a huge sea change in the electorate,'' says Democratic consultant Bill Carrick, who notes that only 25 percent of California voters today were registered in 1992.
The state has never elected a black or Hispanic candidate to the U.S. Senate. Only one Asian-American has cracked that barrier: S. I. Hayakawa, the son of Japanese immigrants, who served from January 1977 to January 1983.
In her announcement, Harris alluded to the state's diversity, saying she would build a campaign "that reaches every community of California.''
In Boxer's first election, Hispanics accounted for 8 percent of the overall tally. In November's elections, exit polls found nearly 2 of 10 votes came from Hispanics, essentially doubling their clout over that time.
Asian-Americans notched 4 percent of the vote in 1992, surveys found, but that nearly tripled to 11 percent last year.
Those changes have loosely followed population growth. The number of registered voters in the state increased by 3.5 million between 1994 and 2012. Nearly 90 percent of those new voters were Hispanic or Asian-American, according to the independent Field Poll.
Hispanics made up about a quarter of the population when Boxer was elected; they now make up about 40 percent of the total of 38 million. Asian-Americans accounted for 10 percent of the population in the first Boxer run. They now make up 13 percent, according to the Census Bureau.
The state's demographic shifts have been a difficult adjustment for Republicans. In the 1980s and early 1990s, GOP candidates running statewide sometimes rolled up more than 40 percent of the Latino and Asian-American vote. But a turnaround came with Proposition 187, which prohibited people who entered the U.S. illegally from using health care, education or other social services.
The 1994 law enacted with encouragement from Republican Gov. Pete Wilson was eventually overturned, but it left lingering resentment with many Latino and Asian-American voters just as their influence began to grow.
Most of California's new voters are Hispanic, and they tend to register as Democrats or as independents. Republican voter registration has withered to 28 percent, while Democrats hold 43 percent.
This dominance could, however, create an opportunity for the GOP. Some analysts have suggested that a big field of Democrats could dilute the party's vote in the Senate primary, allowing one or two Republicans, Assemblyman Rocky Chavez of Oceanside is among those considering a bid, to slip into a November runoff.
Since 2012 the state has used what's called a top-two primary in which all candidates appear on a single ballot. Voters are permitted to pick anyone on the list, but only the two attracting the most votes advance from the primary to November, regardless of party affiliation.
In a Southern California congressional race in 2012, so many Democrats ran in the primary that they canceled each other out, sending two Republicans to a runoff in a Democratic-leaning district. U.S. Rep. Gary Miller ended up winning the seat.
The top-two system has never been tested in a competitive statewide race that could attract a string of credible, well-funded Democrats, a group that could include billionaire climate activist Tom Steyer.
A generation ago in California, a political consultant could aim at a mostly monolithic block of older whites, but "now you need to know calculus,'' says Democratic consultant Roger Salazar, alluding to turnout projections and other assessments that must be made of multiple voter groups.
"The best political consultants of the future,'' he says, "are going to have to have a math degree along with political science.''
