Heading into 2019, he may turn up the heat even more, buoyed by his overwhelming endorsement from voters, a Democratic U.S. House and a more aggressive governor who takes office Monday.

Becerra kicked off the new year on Thursday by leading a coalition of 17 Democratic attorneys general in appealing a recent ruling by a conservative federal judge in Texas that declared the Obama-era Affordable Care Act unconstitutional. The law that Becerra called the "backbone of our health care system" will remain in place while the case is considered by the 5th U.S. Circuit Court of Appeals in New Orleans.

In all, California's first Latino attorney general says he has filed or joined more than 100 briefs and other legal actions — including 45 lawsuits — against the Trump administration, mostly targeting its environmental and immigration policies. He has scored some significant victories, most notably in defending former President Barack Obama's "Dreamers" program that protects hundreds of thousands of young immigrants from deportation, and in defending the bulk of California's so-called sanctuary laws that limit state cooperation with federal immigration agents.

"We're going to keep respecting immigrant families, like my own, who work hard to build a better California," Becerra said at one of the numerous news conferences he has held in English and Spanish, sometimes twice in one day, to criticize Trump policies.

Trump once threatened to pull all immigration agents out of California, which he predicted would create a "crime mess like you've never seen."

Becerra, 60, was appointed attorney general by departing Gov. Jerry Brown, and in November won the support of nearly two-thirds of voters over Republican Steven Bailey, a retired judge. Bailey criticized Becerra for reacting to "every tweet coming out of Washington" instead of focusing on reducing crime.

In Democratic-dominated California, however, Becerra's biggest criticism from a Democratic primary opponent, Insurance Commissioner Dave Jones, was that he didn't sue Trump more.

Becerra's campaign website calls him the son of immigrants, although his father, Manuel, was born in Sacramento and grew up in Mexico. His mother, Maria Teresa, was born in Mexico and came to the United States after marrying his father.

Becerra says his father "was more immigrant than my mom" because he spoke Spanish on road construction crews, while his mother spoke English at her clerical jobs.

He mentions his parents at every opportunity and used to wear his father's wedding ring as his own.

Becerra's longtime friends also credit his parents for his success.

"Hard-working, commitment to education, strong integrity and character: He never wavered from those values," said former California Democratic Party Chairman Art Torres, a longtime state legislator who gave Becerra his first political job running Torres' state Senate office in Los Angeles.

Becerra quickly learned the benefits and pitfalls of L.A. Latino politics when he moved there in 1986 to take the job.

Within a few years he went from becoming an assistant attorney general to winning an open state Assembly seat after he says his wife, a perinatologist (an obstetrician who specializes in high-risk pregnancies), told him to "get it out of your system."

He almost immediately began campaigning for an open congressional seat and was elected to the first of 12 two-year terms. There he made immigration and health care issues a priority as he rose to become Democratic caucus chairman before Brown picked him in 2016 to replace Kamala Harris, who won a U.S. Senate seat.

"It was really a meteoric rise," said David Ayon, a senior fellow at the Center for the Study of Los Angeles at Loyola Marymount University and an analyst at the political opinion research firm Latino Decisions. He has known Becerra since they attended Stanford University at the same time.

Becerra was among the first of a "new generation of Latino candidates in Southern California that were really highly educated — young, energetic and had the appearance of being these Boy Scouts," said Ayon, co-author of "Power Shift: How Latinos in California transformed politics in America."

Don Thomas, who has known Becerra since kindergarten, said Becerra learned to stay calm and self-controlled in high school as a varsity golfer and an exceptional poker player. Becerra studied the advice of famous golfers even as he practiced with a set of used clubs costing less than $100.

"I'm going to read about it, I'm going to study it, then I'm going to practice my ass off," Thomas said. "That's just the way he went about things."

Teachers and friends routinely mispronounced Xavier, sometimes nicknaming him "Zav" or "X." Becerra didn't start correcting them with the proper Spanish pronunciation, "HAH-vee-air," until college.

Unlike his father, Becerra recalls no overt discrimination but cringes when remembering how, nearly 30 years ago as a young politician, two women at a chamber of commerce reception told him, "We like you a lot; you blend so well."

Lori Kalani, co-chair of the Cozen O'Connor law firm's state attorneys general practice, represents business clients who often aren't particularly happy with California's aggressive environmental and consumer protection laws, like its nation-leading internet privacy law. But she credited Becerra with being a quick learner and being "extremely open-minded to opposing opinions."

Critics from both parties said his concentration on Trump means his office neglects other core duties, like combating opioid misuse or seizing guns from those no longer allowed to have them.

Becerra said he intends to devote more of his agency's time to priorities including white collar crime, elder abuse and human and sex trafficking. But he created new bureaus to protect the Affordable Care Act, women's reproductive rights and environmental laws, he said, "to defend the people, the values and the resources of our state."

The attorney general's office has long been a stepping stone for politicians, including Brown and Harris, and Becerra's rise fueled speculation about a future bid for governor or U.S. Senate. Becerra ran unsuccessfully for Los Angeles mayor in 2001, explored a Senate run before his appointment, and was mentioned as a possible vice presidential candidate in 2016.

The attorney general's office gives him a "perfect platform" for moving up, said Torres.

"But I don't think he's in any rush to do so. He's very thoughtful, methodical, in how he proceeds," Torres said. "I don't think there's anything that's beyond his reach when he's ready to move."