Regardless, Newsom's feuds with the Republican president attracted much attention. Perhaps the most consequential was the Trump administration's efforts to stop California from continuing to set its own auto emissions regulations. In response, Newsom teamed with four major automakers to go against Washington.
When he wasn't battling with the president, Newsom was advancing policy at a frenetic pace. He began the year by placing a moratorium on executions for the more than 730 people on California's death row, the largest in the Western Hemisphere. The move won praise from criminal justice reform advocates and scorn from families of people killed by convicted criminals who had been sentenced to death.
Elsewhere, he checked off a litany of items in his progressive wish list. Among them: health care to more young immigrants living in the country illegally, expanded subsidies for middle-income people to buy health insurance, an increased tax credit for working families, a ban on for-profit prisons, and stricter rules for when police use deadly force.
All of the moves drew sharp criticism from the state's Republican minority, and some California residents have started a long-shot campaign to recall Newsom from office.
Newsom stumbled at times on message, sowing confusion early on about the future of California's troubled high-speed rail project and injecting last-minute uncertainty into an impassioned debate over exemptions for childhood vaccinations.
Assembly Speaker Anthony Rendon, a fellow Democrat, said it's been a year of learning between Newsom and lawmakers after eight years of dealing with Gov. Jerry Brown.
“We’ve had an incredibly productive year, and I consider him a partner, and I know he is willing to work through things," Rendon said.
Atkins, however, found herself at odds with Newsom when he vetoed her bill aimed at blunting environmental rollbacks from the Trump administration. Environmental groups, normally allies, were upset.
“I think he had some growing pains that were frustrating in the first year,” said Kathryn Phillips, director of the Sierra Club California.
Homelessness has become a top issue in California, and Trump took delight in highlighting the problem, saying the state's major cities were “going to hell.”
Newsom has touted a $1 billion investment the state made in 2019 to address homelessness and the law he signed enacting a statewide cap on annual rent increases to help address the lack of affordable housing. But those moves have yet to produce visible results.