WASHINGTON — When Joe Biden took office as vice president in 2009, he was part of an administration inheriting the worst economic crisis in generations.

His second stint in the White House begins Wednesday under even more dire circumstances.

First and foremost he faces the coronavirus pandemic, a health and economic disaster that is now killing around 4,000 Americans per day — worse than a daily 9/11 — has left some 11 million without jobs and millions more facing lost income, isolation, and an uncertain future.

He will be inaugurated in the shadow of a Capitol that two weeks earlier saw one of the ugliest moments in U.S. history: an insurrection aiming to overturn a democratic election. A Confederate flag was paraded through the Capitol that day, crystallizing the depths of the country’s festering divisions and racial animus. Uniformed soldiers and barbed wire now ring the Capitol.

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Even as he pledges national healing, Biden will have to govern as the polarization and misinformation that drove that tragedy still run rampant, and with the cloud of a Senate impeachment trial that could extend President Donald Trump’s dominance of the national discussion.

And he’ll try it all with only the narrowest Democratic control of Congress.

“There are more challenges and they are more substantial than what even Barack Obama and Joe Biden faced when they came in,” said Sen. Bob Casey (D., Pa.), a staunch Biden ally.

Casey said the economic problems are equal to or worse than those in 2009, on top of the health crisis. “The divisions in the country are also more substantial,” he said.

It’s not unusual for new presidents to come into office aiming to clean up messes left by their predecessors, said Julia Azari, a political scientist at Marquette University. In the case of Biden and COVID-19, though, “once that’s dealt with, there are five other crises.”

Biden will be joined in office by a barrier-breaking vice president, Kamala Harris, the daughter of Jamaican and Indian immigrants who will become the highest-ranking woman ever in American government.

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He has presented himself as a figure of competence, stability, and empathy for a nation that has endured a chaotic four years and much suffering over the last nine months — and any sense of normalcy still seeming far off. For many, Biden’s campaign message wasn’t the most exciting, but presidential historian Timothy Naftali said it may be exactly what’s needed.

“A good-paying job and good health will excite Americans,” said Naftali, a professor at New York University. “We might have had enough political excitement for a while. In fact, I’m sure of it.”

Biden effectively took on the mantle of national leadership Thursday even before his inauguration, rolling out a proposed $1.9 trillion coronavirus relief package and giving a national address meant to convey his sober approach to the issue.

“A lot of this is just about the leadership that he can bring to bear, both he and Kamala Harris, but also the leadership of individual agencies, communicating effectively, communicating consistently, having competent leadership,” Casey said.

The Trump administration has presided over the rapid development of a coronavirus vaccine, which offers hope, but the president has also long downplayed the pandemic, and public safety measures, even as it surged again and again.

Casey blasted Trump for spending months focused almost entirely on overturning the election, as the vaccine rollout has stumbled. “Leadership alone will be filling a huge void,” Casey said.

Biden has pledged to have 100 million vaccine shots administered in his first 100 days in office, calling it “one of the most challenging operational efforts we have ever undertaken as a nation.”

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It will take time to see if his plans and execution are effective. What he can do immediately is change the tenor from the country’s top office.

In his speech Thursday he talked about unity, “a crisis of deep human suffering,” and expressed empathy for those who have lost jobs or loved ones. “I know that feeling, looking at the empty chair across the table,” said Biden, who lost his first wife and daughter in a car crash, and, decades later, a son to cancer.

“The fact that people are suffering so much right now, it’s important to have a leader who genuinely, genuinely cares about their plight,” said Alison Dundes Renteln, a political science professor at the University of Southern California.

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Those who supported Biden will be looking for “a certain level of selflessness and humility that we have not seen in the current administration,” along with “technocratic competence,” said Andra Gillespie, a political scientist at Emory University.

Unlike his two predecessors, Biden isn’t a celebrity or cultural symbol. Obama and Trump each inspired devotion and vitriol because of who they were, but also what they represented. Biden doesn’t carry that kind of cultural weight.

“You have two of the most notable and famous and distinct people to serve in the presidency for wildly different reasons, and you start to lose sight of having someone who isn’t so culturally symbolic in there,” Azari said.

In that sense, Azari said, Biden’s tenure will be a test of what the presidency is after two predecessors who were each, in their own ways, bigger than politics.

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For all the hope Biden supporters place in his experience, he’ll face significant obstacles, including the raging political divides that show few signs of abating. Somewhere between two-thirds and three-quarters of Republicans harbor doubts about the fairness of the election, polls have found, after the relentless campaign by Trump and his allies to attack it with false claims.

“The problem that he’s going to face, and that Obama faced, is that all Americans won’t believe that he’s their president,” said Lilliana Mason, a University of Maryland professor who has studied polarization. “He is trying to govern a country that doesn’t agree on what reality is.”

Even basic health measures, like wearing face masks, have become cultural flash points. Biden on Friday slammed House Republicans who refused to wear masks when in a confined, secure space with fellow lawmakers during the riot. “What in the hell’s the matter with them?” he said.

On policy, Democrats will have almost no room to maneuver in Congress, given their slim control of both the House and the Senate. And Republicans are sure to oppose many of his key policy plans, labeling them too expensive, or as federal overreach. A day after Biden unveiled his coronavirus relief plan, Sen. Pat Toomey (R., Pa.) blasted two major elements, $1,400 relief checks and a nationwide $15 minimum wage.

» READ MORE: First it was ‘fraud,’ then they just didn’t like the rules: How Pa. Republicans justified trying to overturn an election

Biden allies hope his experience in the Senate can help break through the gridlock, though there’s also deep skepticism that’s possible.

“I don’t think we’ve had a president with as much combined legislative and executive experience,” Casey said. “On a lot of days that will matter.”

Even as Biden tackles the immediate challenges, Gillespie noted that Black Americans — who were crucial to his victory — will look for him to deliver on his promises to address issues of race and inequality that roared to the forefront over the summer.

“There is a younger group, particularly of African American activists, who are emerging who are not going to be satisfied with symbolic gestures,” Gillespie said.

» READ MORE: Pat Toomey is ready to work with Joe Biden. A little.

It will be crucial, she said, for Biden to make clear that even as he confronts the virus, issues such as police brutality, voting rights, and structural inequality remain on the agenda. Some of that can come through addressing the underlying health and economic issues that have meant Black, Latino, and indigenous groups have suffered disproportionately from the pandemic, Gillespie said.

Biden explicitly pointed to that unequal impact Friday, saying “Equity is central to our COVID response.”

Harris’ exact portfolio within the administration isn’t yet clear, and it’s likely she’ll have to spend significant time in the Senate to cast tie-breaking votes in a chamber split 50-50. But even before she takes up a policy role, she’ll fill a symbolic one.

Her perspective, as a woman, and a woman of color, can influence policy discussions “in ways and conversations that you don’t expect,” Azari said.

Biden on Thursday called for unity to “build a bridge to the other side of the crisis we face.”

“We didn’t get into this overnight,” he said. “We won’t get out of it overnight, and we can’t do it as a separated and divided nation.”