SAN FRANCISCO — Gavin Newsom was sworn in Monday as California's 40th governor, a powerful part of the recent Democratic wave that vows to oppose many White House positions in the latter half of the Trump presidency.

"I want to be clear, we will be bold, we will aim high and work like hell to get there, and we will offer an alternative to the corruption and incompetence of the White House," said Newsom, 51, backed by a huge state seal and accompanied by his wife, Jennifer Seibold Newsom, and their four children.

"Our government will be principled and always on the side of the people," Newsom said. "We'll have the courage to do things right even when they are hard. We will be a California for all."

In his speech, Newsom made clear he plans to use his state – a cultural melting pot with the world's fifth largest economy – as a bulwark against Trump policies that candidate Newsom decried as misguided and racist. Trump, in turn, has called Newsom a "clown" who wants "open borders."

Newsom's swearing-in ceremony was not met with universal cheer. According to reports from KGO-TV, some protesters yelled "I object" during the ceremony, before being drowned out by supporters shouting "Gavin, Gavin!" The protesters were later removed.

While Newsom now will have to work with the White House when it comes to requesting federal relief after wildfires and other disasters, there is no indication a man whose closest confidants suggest he has aspirations for national office plans to play nice.

"California is our home, and in our home every child should be loved, fed and safe," Newsom said, almost upstaged by his 2-year-old son, Dutch, who paraded around the stage during his father's speech.

"We have four children, and nothing is more important than giving them a good, happy life," he said, smiling. "But that shouldn't be just for the children of a governor and a filmmaker, and children shouldn't be ripped away from their parents at the border, or left hungry when politicians seek to pour billions into a wall that should never be built."

The line was met with raucous cheers by those piled into a tent erected to guard against hard rains that have fallen across northern California in recent days.

But Newsom does step into the statehouse with the wind at his back. This is the first Democrat-to-Democrat governorship handover in the state since the late 1800s, with Newsom taking the reins after eight years of Jerry Brown's fiscally conservative stewardship.

Newsom also has a natural political ally in newly re-minted House Speaker Nancy Pelosi, a fellow San Franciscan. Pelosi was at the inauguration, and her appearance was met by a mix of applause and boos.

Impressive Democratic wins across the state last November, especially in traditionally conservative strongholds south of Los Angeles, have also given Democrats a supermajority in both houses of California's Legislature.

Among the challenges facing Newsom as he takes office are a variety of pre-existing problems that he has vowed to tackle without providing many specifics.

These include a roiling homelessness issue, with California accounting for 25 percent of Americans who live on the streets; a growing income inequality gap that finds even those working in the booming tech industry struggling to make ends meet; and inefficient early childhood education programs, which Newsom plans to address with up to $2 billion in spending.

Newsom, whose career as a businessman and politician has made him close with many of the state's more powerful figures, told USA TODAY during his campaign last fall that he plans to ask some tech billionaires to pitch in, particularly on housing issues, including Apple CEO Tim Cook.

“I’m going to say, ‘Tim, let’s get together this week,’” Newsom said at the time. “’Congratulations, all these (corporate) tax cuts and repatriated (overseas) earnings present an extraordinary opportunity to make investments in your backyard, ones that address your fiduciary responsibilities to your shareholders but also recognize the broader, negative social issues that have been the unintended byproduct of your success.”

During his inauguration speech, Newsom addressed a variety of issues facing the state but did not reveal how he planned to tackle them, whether it be the state's growing and deadly wildfires, or its pro-immigration policies.

Instead, the telegenic politician – who has made clear his admiration for slain U.S. Sen. Robert Kennedy – won points with the partisan crowd with lines touting "a Marshall Plan for affordable housing" and promising that all state citizens would have access "to quality and affordable health care."

In one passage, Newsom hit on a host of promises: "We will use our market and moral power to demand fair prices for prescription drugs. We’ll stop stigmatizing mental health and start supporting it. And we’ll always protect a women’s right to choose."

In closing, Newsom invoked familiar and powerful imagery of the California dream, which he implied should be available not just for the lucky few.

"From Sutter’s Mill (where gold was discovered) to Steve Job's (Apple) garage, this has been a place where anything’s possible," Newsom said. "But you shouldn’t have to find gold or create a billion-dollar startup to live the California dream, it’s for everyone."

Follow USA TODAY national writer Marco della Cava: @marcodellacava