California Governor Gavin Newsom takes the oath of office from state Supreme Court Chief Justice Tani Gorre Cantil-Sakauye as his wife Jennifer Siebel Newsom looks on during his inauguration Monday, Jan. 7, 2019, in Sacramento, Calif.

California Democratic Gov. Gavin Newsom ripped the Trump administration and its policies during his inaugural address Monday while also taking a swipe at President Donald Trump himself, without mentioning him.

"Here in California, we will prove that people of good faith, and firm will can still come together to achieve big things," Newsom said. "We will offer an alternative to the corruption and the incompetence in the White House. Our government will be progressive, principled and always on the side of the people."

He also spoke about the state standing up against Washington's policies on everything from the environment, immigration and LGBT rights to women's reproductive access. Newsom and Trump have traded barbs in the past and just last week the California politician blasted the president's threat to close the southern border as "irresponsible, irrational and absurd."

Newsom, 51, is the Golden State's 40th governor and succeeds Jerry Brown, a Democrat who served four terms as governor and also sparred with the Trump on a wide range of issues, including climate change and immigration. Early in his remarks, Newsom thanked House Speaker Nancy Pelosi, D-Calif., but then added that "there is an administration in Washington that is clearly hostile to California values and California's interests."

Prior to becoming governor, Newsom was the state's lieutenant governor and before that mayor of San Francisco. Newsom made his mark early on as mayor, ordering the city-county clerk in February 2004 to issue same-sex marriage licenses.

"So 15 years ago, when I was a new mayor and I heard politicians in Washington sneering at 'California values' and attacking our LGBTQ community, I remembered what my father taught me: That 'it's never the wrong time to do the right thing.' And that's what we did."

Newsom continued: "Just like 15 years ago, now is a time for courage. We will stand up for what's right, and we will defend our people. My pledge to every Californian is this: no matter what comes at us, I will have your back."

The new governor called the nation's most populous state "a giant engine of commerce — the most creative and entrepreneurial in the world." He also sought to contrast the blue state's values with division elsewhere in the country.

"At a time when so much of America is divided, we are united," Newsom said. "Our people are big-hearted [and] fair-minded, and those qualities are more vital now than ever."

Newsom won the election in November with a margin of victory of more than 20 percentage points against Republican John Cox, a businessman Trump had endorsed.

"I intend to represent all Californians, not only those who voted for me," Newsom said.

The Democrat spoke about the federal government taking children away from their parents at the border as well as kids "left hungry while politicians seek to pour billions into a wall that should never be built." Newsom also recalled a recent visit to San Diego where he met with volunteers providing help "to desperate migrants who others treat like criminals."

At the same time, Newsom pledged to do more to help children in his own administration. "We will support parents so that they can give their kids the love and care they need...especially in those critical early years of life," he said.

Newsom also took a shot at drug companies for "sky-high prices" as well as "a gun lobby that's willing to sacrifice the lives of our children to line their pockets." He also criticized polluters and payday lenders for what he said was preying on "our most vulnerable" and vowed "we have the power to stand up to them – and we will."

California enjoys "a booming economy" but Newsom said it still faces "serious challenges – some that have been deferred for too long." He cited "a gulf between the rich and everyone else" plus a homeless crisis and "an achievement gap in our schools and a readiness gap that holds back millions of our kids."

According to Newsom, "These aren't merely policy problems. They are moral imperatives."

There was a brief moment on levity during the speech when Newsom's 2-year-old son, Dutch, went on stage with a pacifier in his mouth during his father's speech. Newsom and his wife, Jennifer Siebel Newsom, have four young kids.

Newsom campaigned for governor with ambitious plans for everything from single-payer health care and affordable housing to childhood poverty and universal preschool. The promises raised cost concerns from some taxpayer groups even before Newsom took the reins Monday.

"In our home, every person should have access to quality, affordable health care," Newsom said. "Far-away judges and politicians may turn back our progress. But we will never waver in our pursuit of guaranteed health care for all Californians."

After taking office Monday, Newsom signed a "first-in-the-nation order to create the largest single purchaser for prescription drugs," according to a press release issued by his office. He also proposed for his first budget to move the state "closer to health care for all," including providing coverage to young undocumented immigrants through Medi-Cal.

Newsom also pledged Monday to launch "a Marshall Plan for affordable housing" as well as to elevate "the fight against homelessness from a local matter to a statewide mission." California has about 12 percent of the U.S. population but approximately one-quarter of the nation's homeless population.

Meantime, Brown spent the last few years in the governorship pushing fiscal restraint and the need for state lawmakers and the next governor to sock away more money for the next economic downturn. Newsom enters office as governor with California — the fifth-largest economy in the world — having about $14 billion in the state's rainy day fund, and several billions in surplus.

"We will prepare for uncertain times ahead," Newsom said. "We will be prudent stewards of taxpayer dollars, paying down debt and meet our future obligations. And we will build and safeguard the largest fiscal reserve of any state in American history."

Yet Newsom quickly added: "But I want to be clear. We will be bold. We will work like hell to get there."

Newsom also repeated the "courage" theme of his gubernatorial campaign. "I know courage is a word that means different things to different people. But for me, courage means doing what is right even when it's hard. That will be the foundational mission of our administration."