As a Democratic primary candidate, Joe Biden told debate viewers he understood that most Americans “are looking for results, not a revolution.” He promised wealthy donors that, in a Biden administration, “nothing would fundamentally change.” And he declared to rallygoers that he saw himself “as a bridge, not as anything else,” to a new generation of Democratic leaders.

Then covid changed everything.

By the time Biden ascended to the presidency, he had refashioned himself as a transformational leader — a president prepared to fundamentally overhaul the role of government in society on behalf of the nation’s working men and women.

The pandemic — which had killed half a million Americans by the beginning of his second month in office — provided an organizing principle for Biden’s presidency and a clear mission for him to manage. But the coronavirus also exposed deep-seated inequalities, from systemic racism to a fragile middle class, just one illness or missed paycheck away from free-fall.

President Biden warned about rising coronavirus cases in the U.S. on April 6 and urged precautions to guard against the coronavirus. (The Washington Post)

Biden came to office citing four major crises — the coronavirus, the economy, racial inequity and climate change — and with those emergencies came an opportunity to go big and bold and ambitious and to push through massive legislation with or without the support of Republican lawmakers in Washington.

In a nod to history, Biden has installed a huge portrait of Franklin D. Roosevelt as the focal point of the Oval Office.

“Pre-covid, I never thought he would be an incremental president, but I thought he would be taking the next couple of big steps. Now, the situation has made him take leaps,” said Greg Schultz, a longtime Biden adviser who managed his 2020 presidential campaign during the primary. “Biden knows Americans don’t want you to shake things up just to shake things up, but Biden is now left with a world that has been shaken up — because of Trump and covid and the way Trump handled covid — so Biden is left, in some ways, with a country in pieces.”

Biden’s first 100 days in office reveal a leader who views his mandate in existential terms — waging “a battle for the soul of the nation,” as he has put it, and taking actions that will help set the course of the country for decades to come.

He has sought to redefine bipartisanship, appealing less to Republicans in Congress and more to voters and elected officials nationwide. A successful bill in a Biden administration has a majority of support from across the country, even if it attracts no Republican votes.

And so far, Biden has largely assuaged the concerns of both the left and middle, appearing moderate in tone and temperament while pursuing many of the liberal policy prescriptions favored by his party’s base.

“The secret sauce is that his persona is reassuring and comforting to moderate and independent voters, and his polices are comforting and reassuring to progressive voters,” said Rahm Emanuel, the former mayor of Chicago who also served as President Barack Obama’s chief of staff. “And there’s an authenticity to Joe Biden that makes it hard to demonize him as a radical villain.”

Many Republicans, however, argue that Biden has indeed taken a radical turn. Sen. Lindsey O. Graham (R-S.C.), who has known Biden since their days in the Senate, recalled Biden’s reputation as “a Steady Eddie” and a politician who has “always been progressive but somebody you can do business with.” He said he was “surprised” by what he’s seen from Biden as president so far.

“The first 100 days have been about executive orders and reconciliation,” Graham said, referring to a procedural rule that allows some budget bills to be passed with a simple majority. “I just thought, with Joe, he would turn the heat down a little bit. I don’t see the heat turned down at all. I thought he’d be more engaged.”

Graham added: “I think he’s decided that his presidency is going to be big and transformational and partisan.”

Allies and advisers say Biden arrived at the presidency as a politician versed in strategy and dealmaking — with 36 years in the Senate and eight as Obama’s vice president — and as a person versed in loss. He has buried half his immediate family — his first wife, Neilia, and infant daughter, Naomi, who died in a car crash in 1972; and later, his adult son Beau, who died of cancer in 2015.

At 78, Biden is professionally at peace, his allies say, with much he hopes to accomplish but little left to prove. He views the presidency as a capstone, not a steppingstone, and he brings to it a belief he can unify a riven nation.

“History creates moments for leaders, and I’m not sure that in another time Joe Biden would be president of the United States,” said David Axelrod, a former top Obama adviser. “But he was uniquely suited for this time — his empathy, his calm, his experience were all qualities that this moment called for.”

Biden’s first legislative act as president was passing a $1.9 trillion covid relief package — its contours almost entirely unchanged from his initial proposal — without any Republican votes. Now, he is pursuing a roughly $2.3 trillion infrastructure overhaul that includes not just physical projects like roads and bridges, but also billions for Democratic priorities — climate change; home- and community-based care for elderly and disabled people; and public schools, early learning centers and community colleges.

He plans to pay for it by increasing taxes on corporations and wealthy individuals and, despite robust bipartisan outreach, has again signaled a willingness to push the package through with only Democratic votes.

“The sum total of what he’s doing feels radical, but the individual things he’s promising are not that radical,” said Shailagh Murray, who served as Biden’s communications director and deputy chief of staff when he was vice president. “This is what competent, responsive government is supposed to look like.”

As he approaches the 100-day mark, Biden is also nearing the end of the scripted part of his presidency.

He faces an immigration crisis at the nation’s southern border, a searing debate over policing reforms in the wake of a guilty verdict in the murder of George Floyd and pressure to enact stricter gun controls amid a tide of mass shootings. Mike Donilon, a senior adviser, said Biden’s life experiences have prepared him to adapt to sudden changes.

“He knows that life can always throw you a curveball, so what does that mean for his leadership?” Donilon said. “It means he understands how hard life can knock you down — he knows how tough it can be — and so he has enormous respect for people who struggle through it every day.”

In the early weeks of the pandemic last year, both Biden and Sen. Elizabeth Warren (D-Mass.) lost someone close to them to the coronavirus. For Biden, it was his longtime adviser Larry Rasky, and for Warren, it was her oldest brother, Don Reed Herring.

Warren recounted how, in a phone call between the two shortly after those deaths, Biden “could in the same sentence about policy and health care tear up about what it means to lose someone you love.”

Some of the ideas they batted around during that conversation — the importance of community health centers, improved access to coronavirus testing and vaccination — ended up being reflected in the covid relief package he signed into law as president.

“To me, that’s Joe Biden,” Warren said. “He understands policy, he lived his entire adult life in the Senate, he understands bills and strategy. But more than anything else, he understands pain and hope and fear and how the decisions we make as a people through our government can make lives better or much, much worse.”

Liberals like Warren have been largely pleased with how Biden has governed so far, especially given his reputation during the primaries as a centrist. His allies and advisers say he was always bolder than the activist class gave him credit for: “Maybe that’s because Candidate Biden was a caricature, and they never really took the time to look at who Joe Biden was,” said senior adviser Anita Dunn.

A Washington Post analysis of his voting record as a senator found that while Biden was generally in the top 25 percent of the most liberal members of the Senate overall, among Democratic senators, he fell squarely in the middle.

Biden has often seemed to have a strong sense of where the Democratic Party is moving. As vice president in 2012, he went off-script when he came out in support of same-sex marriage in response to a question on NBC’s “Meet the Press” — frustrating the White House by getting ahead of Obama, who had not yet made a public declaration.

“Biden is closer to the average American than just about anyone in D.C.,” Schultz said. “He just has a gut feeling, and maybe it’s through life’s tragedies, maybe it’s through Scranton, but if you were to give Joe Biden an issue and say, ‘Describe where the average American is on it,’ I bet you Biden would get closer to the average American than any Democratic consultant, pollster or data scientist.”

Biden also became president at a moment when several conjoined crises created an openness among the public for government to play a more prominent role.

Those four crises that Biden identified, White House Chief of Staff Ron Klain said, helped form “the four pillars of his presidency.”

“It’s hard to look at the pandemic or the George Floyd killing or where we are with infrastructure or where we are with climate change and wildfires and the rest and not say, ‘Hey, it’s time for government to step up,’ ” Klain said.

So far, Republicans have struggled in their attempts to vilify Biden or paint him as an out-of-touch, big-government socialist. A move by Sen. Ted Cruz (R-Tex.) to depict Biden as “boring but radical” fell flat.

As Andrew Yang — a 2020 Democratic presidential primary candidate now running for mayor of New York — put it last year: “The magic of Joe Biden is that everything he does becomes the new reasonable.”

Sen. Susan Collins of Maine, a moderate Republican who has known Biden since their days in the Senate, seemed to articulate the challenge of many Republicans, explaining that while she personally has a deep affinity for the president — “I still find him to be a very likable, warm person,” she said — she is alarmed by what she views as Biden’s shift to more divisive policies.

“I’ve always thought of him as being center-left, but not left, and in the presidency, whether it’s with the encouragement of his staff or due to the extraordinary pressure that the outside progressive groups can apply, he seems to me to have moved substantially to the left,” Collins said.

Rep. Pramila Jayapal (D-Wash.), chair of the Congressional Progressive Caucus, said Biden is able to offer a bolder vision for the country than many activists and liberal lawmakers expected because of the specific commingling of the man and the moment.

“He is a White guy in a country that still values the words of White men, and so whether or not he and, say, I or Alexandria are using the same words, the fact is, we still have a country that values the words of White men more,” Jayapal said, referring to Rep. Alexandria Ocasio-Cortez (D-N.Y.).

Many of Biden’s proposals, she added, “are popular ideas that resonate with workers everywhere, but I can guarantee you Joe Biden talking about that goes off better, because I happen to be a Brown immigrant woman — and he’s the president, too.”

Murray described Biden as “one of the most adaptive politicians we’ve seen,” saying the 46th president is “a person who has evolved and changed and adapted and is now leading in this moment in a form that is the sum of many parts, of all these different phases and experiences he’s had.”

Biden has talked about reading Jonathan Alter’s “The Defining Moment,” a book about Roosevelt’s first 100 days. In June — right around the time he became the presumptive Democratic nominee and covid had ground the country to a halt — Biden began speaking in more revolutionary terms, promising a transformational administration in which government plays an outsize role in solving the nation’s challenges.

Biden’s self-styled Roosevelt analogy has been encouraged by some — Alter called Biden “FDR’s heir” in a New York Times op-ed — but dismissed by others. One liberal magazine, the New Republic, argued this month that Biden “isn’t close to being a historic president yet,” while the National Review, a conservative publication, ran a recent piece entitled “Biden’s stalled revolution: He’s not FDR. He’s not even Obama.”

Klain said he thinks there are some parallels between the two men — “there’s no question about it in terms of the kinds of crises both men face entering the Oval Office,” he said — while rejecting the comparison overall.

“Joe Biden being president is like Joe Biden,” Klain said. “His presidency is successful because it’s authentically him.”