Kamala Harris and Gavin Newsom appear best-placed in the strongly Democratic state but Antonio Villaraigosa or Tom Steyer could also challenge

Barbara Boxer’s announcement on Thursday that she will not seek re-election to the US Senate next year has shone a light on the Democrats and progressives tipped to succeed her in deep-blue California. Eric Garcetti, the mayor of Los Angeles, and Sheryl Sandberg, chief operating officer of Facebook, quickly signalled they were not interested, leaving four frontrunners to take the seat.



Kamala Harris, 50

The state attorney general is a fast-rising Democratic star. Born in Oakland to an Indian mother and a Jamaican American father, she is popular with the young and ethnic minorities and has twice won election as California’s top law enforcer – the first time beating a tough Republican challenge. Harris made a name for herself by focusing on the mortgage industry, human trafficking and school truancy.

At an April 2013 fundraiser, President Barack Obama called her the “best-looking attorney general in the country”, a remark for which he later apologised. Harris has also been tipped for governor – after Jerry Brown completes his fourth and final term – and the US supreme court.

Gavin Newsom, 47

The gay community reveres the former San Francisco mayor for issuing same-sex marriage licenses in 2004, blazing a path which others followed. In 2009, a premature run for governor ended in a bruising clubbing by Brown, prompting Newsom to find refuge as lieutenant governor, a post he once scorned as ceremonial. He has battled irrelevance, nurtured alliances and visited Capitol Hill last year.

California’s top-two primary system means two Democrats are likely to slug it out in the general election. But a showdown between Newsom and Harris, who each have their base in the San Francisco Bay Area, could split the vote and allow a Republican to squeak on to the final ballot. That scenario, and the fact that other juicy jobs are looming – Brown steps down in 2019 and Senator Dianne Feinstein, 81, is facing calls to step aside when her term ends in 2018 – may, according to the Washington Post, give Newsom and Harris an incentive to divvy things up.

Antonio Villaraigosa, 61

The flashy Los Angeles former mayor has charisma, a moderately successful record at city hall and name recognition. He racked up favours while campaigning vigorously for Obama in 2008 and 2012 and chairing the Democratic National Convention in 2012.

Voters forgave – and some possibly enjoyed – headlines about his turbulent private life: an affair with Telemundo anchor Mirthala Salinas, which ended his marriage, followed by a string of other young girlfriends. Villaraigosa recently moved back to LA after a stint in New York. Anonymous “friends” have signalled to the media he would prefer to run for governor but he has ruled nothing out.

Tom Steyer, 57

The hedge fund billionaire and climate-change activist spent $65m backing green candidates in the 2014 midterms. They got clobbered. But Steyer is determined to stay in philanthropy and politics, giving Democrats a deep-pocketed donor to counter the conservative billionaire industrialists Charles and David Koch. He has money and political debtors but whether he will want to roll in the mud himself remains unclear. An outside bet.