SAN FRANCISCO — By Sunday evening, California Lt. Gov. Gavin Newsom had made up his mind: He wanted to be governor, not senator. But when he tried to call the biggest obstacle to achieving his political ambitions, state Attorney General Kamala Harris, Newsom got her voice mail.

As of Monday afternoon, the two Democrats still hadn’t spoken. But Newsom, who had left a message with Harris outlining his intentions, went ahead anyway and announced on Facebook that he wouldn’t be running for Senate in 2016.


Newsom’s withdrawal capped a furious 72 hours of discussions among the would-be candidates and their advisers over whether to jump at the state’s first open Senate seat in two decades, or hold out for a shot at leading a state that is the world’s eighth-largest economy.

In announcing his plans, Newsom, 47, got out ahead of Harris, 50, who has told friends that she is also interested in the job of governor. Instead, on Tuesday, she will launch a campaign for Boxer’s seat, knowing that if she hesitated, it would appear that she was reluctant to choose the Senate over the governorship. In doing so, she will circumvent a race against Newsom; it has long been assumed that they would avoid a titanic clash that would leave one of them badly wounded, their hopes for higher office potentially derailed.

( Also on POLITICO: Kamala Harris to run for Boxer's seat)

The power play by Newsom, and Harris’s quick reaction, was the latest chapter in a long-running drama between the two leaders of California’s next generation of political heavyweights. For over a decade, the pair have been on a slow but seemingly inevitable collision course — a journey that has its roots in San Francisco, a city that treats its politics like sport.

“It’s just such a dilemma,” said Mark Buell, a prominent Northern California donor who is close to Newsom and Harris. “They’re both so capable that it’s a quandary for Democrats.”

Ahead of his announcement, Newsom solicited advice from House Minority Leader Nancy Pelosi and California Sen. Dianne Feinstein as well as his longtime rival, Gov. Jerry Brown, according to two sources. With Brown, Newsom discussed the field of candidates he might face in a prospective Senate race. Harris, meanwhile, was in touch with New Jersey Sen. Cory Booker. The bold-faced names involved reflect the importance of both candidates to the party’s future and the high stakes surrounding the plum open seat.

Aides to Newsom and Harris said they had spent years discussing their bosses’ ambitions in hopes of heading off an eventual showdown. But both sides were concerned about the appearance that they were somehow engineering a pact. Newsom has been burned in the past: In 2010, he came under fire for pushing through a close ally, Ed Lee, to succeed him as mayor.

It is “nonsense that there is some kind of understanding. It was never the case. That is absolutely not true,” Newsom told The Los Angeles Times on Monday. He hinted that he might back Harris for the Senate seat, calling himself “a huge fan and supporter of hers, and so maybe you can read between the lines.”

Newsom, the son of a former judge, and Harris, the daughter of a Stanford economics professor, both began their careers under the wing of Willie Brown, the legendary Assembly speaker and San Francisco mayor who presided over the city’s political and social spheres. Newsom and Harris were elected to city-wide office in 2003 — he as mayor, she as district attorney. In a city where the political spectrum effectively spans from left to very far left, they both cut reputations as relative moderates.

They immediately established themselves as attractive up-and-comers with a flair for drawing the national spotlight. And among both camps, there was an unspoken rule of political cease-fire.

In 2004, Harris came under heavy criticism after she refused to seek the death penalty for a man who was convicted of killing a San Francisco police officer. Newsom was silent.

Three years later, Newsom found himself in crisis when he admitted to having an affair with the wife of his campaign manager and for having a drinking problem. While much of the city’s political class piled on, Harris resisted.

In 2010, their parallel paths continued when they won statewide office. Newsom was elected to the largely ceremonial post of lieutenant governor, while Harris became attorney general. Both were known to be eyeing higher office, and the potential for conflict only grew.

“You had these two glamorous, interesting figures. They captured the flavor and flamboyance of San Francisco. They made a great pair,” said Nathan Ballard, a former top Newsom aide. “But the attempts to pair them each against each other were always there.”

For all the similarities in their career paths, there were important differences between the two. Newsom is known as being particularly close to former President Bill Clinton, who gave him a valuable endorsement during the 2003 mayor’s race. In 2008, Newsom served as a national co-chair of Hillary Clinton’s presidential campaign. Harris, meanwhile, is seen as closer to Barack Obama: She co-chaired his 2012 reelection campaign and her brother-in-law, Tony West, was a top official in the president’s Justice Department.

The tension between Newsom and Harris mainly surrounded one question: What job did each of them want? Newsom had long been open about wanting to be a governor, not a senator — telegraphing his ambitions, it seemed, to anyone who would listen.

“I’m not surprised about Gavin’s decision because he’s interested in being an executive and not interested in being one of 100 in the Senate,” said John Burton, the state’s Democratic Party chairman.

Newsom’s openness put Harris in an awkward spot. Some close to her thought she was better suited to be governor — a prestigious job that’s been a prime launching pad to run for president in the past. In discussing her political future with her aides, Harris spent most of the time talking about being governor.

Harris will be the frontrunner in the Senate race, but she is by no means assured of victory. Los Angeles Mayor Antonio Villaraigosa has said he is “seriously considering” entering the contest. Tom Steyer, a hedge fund billionaire and environmentalist, is also expected to signal his intentions soon. Democrats, who have a lock on California’s statewide offices, are expected to easily hold Boxer’s seat.

In recent weeks, as it became clearer that Boxer would be stepping aside, Newsom and Harris went out of their way to tamp down talk of a rivalry. Last week, Newsom personally invited Harris to officiate his swearing-in.

The irony of the moment wasn’t lost on them. Just before, he pulled her aside. “I wonder how people are going to react to you swearing me in,” he told her.

Andrew Restuccia contributed to this report.