A former state senator and lieutenant governor, Northam succeeds his friend and benefactor, Terry McAuliffe, after leading a wave election last fall in which Democrats made dramatic gains in the state legislature.
Although his win was powered by Democratic resistance to President Trump, Northam issued a call for civility before some 4,000 guests gathered in the cold outside the state's historic Capitol building.
The scene on Inauguration Day in Richmond as Northam becomes Virginia’s 73rd governor
The audience included at least nine former governors — Republicans and Democrats — as well as Virginia's congressional delegation and members of a legislature that, thanks to the recent elections, features a record number of women and greater diversity than ever.
Invoking lessons learned from his parents while he was growing up among the isolated fishing villages and farms of the Eastern Shore, Northam nodded to his reputation as a less-than-flashy politician.
"It taught me that you don't have to be loud to lead," he said in his thick waterman's accent. He turned and exchanged laughter with the General Assembly's Republican leaders, all wearing traditional gray morning suits.
Perhaps no group was happier to see Northam take office than those Republicans, who mistrusted McAuliffe as overly partisan but view Northam as cut from more familiar cloth.
In remarks that spanned about 20 minutes and opened, literally, with a ray of sunshine after a morning of sparse snow flurries, Northam appealed for Virginia to set a more generous political tone for the entire nation.
"It can be hard to find our way in a time when there's so much shouting, when nasty, shallow tweets take the place of honest debate, and when scoring political points gets in the way of dealing with real problems," Northam said.
Calling on lawmakers to refer to their "moral compass," Northam noted the disparities of Virginia's past and present. Just across the city, he said, Patrick Henry — a Founding Father and former Virginia governor — had called for liberty or death atop a hill while human beings were sold as property at its foot. Today, residents of low-income neighborhoods on one side of the Capitol might expect to live only 63 years, he said, while affluent people in the other direction enjoy life spans 20 years longer.
It is time, he said, finally to do what McAuliffe had failed to accomplish: expand Medicaid to an estimated 400,000 low-income Virginians. Democrats on the platform stood and cheered, while Republicans remained seated and silent.
He also called for protections for a woman's right "to make her own decisions about her health," stronger gun control and spreading economic prosperity more evenly around the state.
But while his agenda drew heavily from Democratic priorities, Northam, who once was wooed by the Republican Party, conceded that "no one has a monopoly on good ideas." He said working together with all parties would be "the guiding principle of this administration."
Northam takes over while Democratic fervor is at a modern high point in Virginia, after elections that remade the clubby General Assembly so that it features the first Latinas as well as its first openly transgender and lesbian members.
While November's blue wave decimated two decades of wide Republican majorities in the House of Delegates, the result is a closely divided chamber — 51 Republicans to 49 Democrats — that will have to work as one to get anything done.
Northam's reputation as a centrist with a deep well of friends on both sides of the aisle gives Virginia a fighting chance to avoid the partisan ills of Washington.
His predecessor, McAuliffe, was hailed for his energy in wooing business to the state but rankled Republicans as the ultimate party operative with long-standing ties to Bill and Hillary Clinton.
GOP leaders were offended by McAuliffe's final State of the Commonwealth address Wednesday night, which called for unity but featured a long list of McAuliffe's accomplishments as he headed out the door as a possible 2020 presidential contender.
"We know Ralph. I can trust Ralph when he gives me his word that he will stick to it," said Republican state Sen. William M. Stanley Jr. (Franklin). "I don't think that we ever had that trust with [McAuliffe]. And so, it's going to be a breath of fresh air around here, even if Ralph Northam is not of the same party and wearing the same color jersey as us on the Republican side. He's somebody that we know and trust."
Areas such as criminal justice reform and education priorities offer common ground for the parties, if they can work together. Republicans think Northam's years in Richmond, as well as his even temperament, will help.
"He obviously knows that culture, he knows how the legislature works," said House Speaker M. Kirkland Cox (R-Colonial Heights), who has been meeting regularly with Northam since the Nov. 7 election. "He's willing to do things behind the scenes. . . . He's just the guy we feel like personality-wise matches up with us."
Northam has also been meeting with the new Democratic members of the House, urging them to learn the way the system operates and to seek good relationships on both sides of the aisle.
It is hardly a progressive call to arms, and Northam risks alienating his own party if he seems too accommodating of Republicans. He refused to engineer a Democratic majority in the House or Senate by luring Republicans into plum state agency or Cabinet appointments, which might have tipped the balance of power. That drew cries of "political malpractice" by some progressive Democrats but won the goodwill of Republicans.
Northam's inaugural speech sought to cast such political gamesmanship as beneath the lofty goals of his office. He issued a series of pledges, including that he "will always tell the truth" and "will always put Virginia's interests first." In what seemed to be a gesture to President Trump, whom Northam dismissed as a "narcissistic maniac" during the campaign, he said he "will work with anyone whose policies help Virginia. And when they do not, I will oppose them."
Northam also told an unflattering story about himself, that early in his career as a pediatric neurologist he had told the parents of an autistic boy that there was nothing he could do to help. The mother saw him years later and said he had taken away their sense of hope.
"I missed the opportunity to provide the one thing her family still needed the most," Northam said. "From that moment on, I have recognized the incredible power of hope and my responsibility to preserve it in the people I serve."
It is hard not to see Northam's influence in the legislature's fragile truce since it convened on Wednesday. Lawmakers quickly shed the rancor of recounts and challenges in close races that had nearly brought Democrats to parity with Republicans in the House. Democrats voted unanimously for Cox as speaker, and one of their number even seconded his nomination with a tribute to his character.
Cox and the Republican leadership then approved operating rules that extended concessions to the newly numerous Democrats, giving them proportional representation on committees and subcommittees. In many cases, Cox assigned Democrats to the committees they wanted.
New Democrats, many of them itching to defy the Richmond establishment, say they are willing to give Northam's moderate approach a chance.
Del. Lee Carter (D-Prince William), who identifies as a democratic socialist, is among the most liberal of the new arrivals. He says he is picking his battles — on health care and the issue of money in politics.
He and other progressives have pledged to reject corporate campaign contributions, and Carter planned to skip Northam's inaugural ball, which is heavily funded by big corporations.
"It's a personal choice. I'm not trying to make a big statement," he said. "I don't feel comfortable going to a Dominion party or Altria party, and this is both. But I'm not asking other people not to go."
Still, there were grumblings Friday that Cox was assigning Democratic bills to a committee that he controls. And Cox has taken pains to point out that his party still has a majority. "We also feel like we have a mandate," he said.
The uneasy peace was evident even in one of this week's most heartfelt tributes to Northam, which came Thursday from a sometimes-adversary: Senate Majority Leader Thomas K. Norment Jr. (R-James City).
With elaborate decorum, an erudite vocabulary and a fondness for pink neckties, Norment is known for sarcastic takedowns of colleagues who cross him or who defy Senate convention. But on Thursday, his voice cracked with emotion as he recalled that Northam helped two of Norment's grandchildren get treatment for serious health problems.
Citing their bonds as fellow alumni of Virginia Military Institute, Norment said solemnly that the new governor exemplifies the school's highest standards.
"His friendship and the compassion and the professional concern . . . touched my family twice," Norment said. "And for that I remain enormously appreciative."
Of course, last year, it was Norment who set Northam up to cast a tiebreaking vote — in his role as lieutenant governor presiding over the Senate — on the issue of sanctuary cities. Republicans then used that vote to hammer Northam mercilessly during the gubernatorial campaign as being soft on criminal immigrants. So the good feelings have their limits.