Updated at 1:54 p.m. ET

Former Vice President Joe Biden has been elected the 46th president of the United States, narrowly emerging victorious from a contentious White House campaign that stretched days past election night, as vote tallies in several swing states were slowed by an unprecedented surge in mail-in ballots.

Biden edged President Trump, who in the days since voting ended has falsely claimed a premature victory and baselessly said Democrats were trying to steal the election. The Trump campaign is still contesting the process in several states.

"The simple fact is this election is far from over," Trump said in a statement Saturday. "Joe Biden has not been certified as the winner of any states, let alone any of the highly contested states headed for mandatory recounts, or states where our campaign has valid and legitimate legal challenges that could determine the ultimate victor. "

Despite the president's rhetoric, Biden's team projected confidence as ballots were tabulated, knowing that large chunks of the vote still to be counted were in diverse Democratic strongholds like Milwaukee, Detroit and Philadelphia.

The Associated Press called the race for Biden on Saturday when it said that Pennsylvania's 20 electoral votes put him over the 270-vote threshold needed to win the Electoral College.

It's a fitting tipping point state. Biden was born in Pennsylvania and launched his campaign with rallies in Pittsburgh and Philadelphia. He spent Election Day visiting his childhood home in Scranton and then rallying supporters in Philadelphia.

"I am honored and humbled by the trust the American people have placed in me and in Vice President-elect [Kamala] Harris," Biden said in a statement. "With the campaign over, it's time to put the anger and the harsh rhetoric behind us and come together as a nation."

Trump had appeared to hold a lead in Pennsylvania on Tuesday night, but the margin was a mirage of sorts, because at the time more than 2.5 million mail-in ballots had not been counted. Biden won the vast majority of those yet-to-be-counted ballots.

The race was closer than preelection polls had suggested, with Trump holding on to contested states like Florida, Ohio and Texas.

But Biden won back the White House the way Democrats vowed to since the day Trump won four years ago: by resurrecting the so-called "blue wall" that Trump dismantled in 2016 — winning Wisconsin, Michigan and Pennsylvania.

Biden was also able to flip longtime conservative redoubt Arizona, according to The Associated Press, and held a narrow lead in Georgia as of early Saturday.

"The soul of the nation"

In topping Trump in a race that was both upended and largely defined by the coronavirus pandemic, the Democratic nominee has become the first challenger to defeat an incumbent first-term president in nearly 30 years.

At 77, Biden becomes the oldest man ever elected president. (He'll be 78 by Inauguration Day.) He's also the first former vice president to win the White House since George H.W. Bush in 1988; the second Roman Catholic in U.S. history elected president; and he'll be the first president to call Delaware home.

And with his victory, his running mate, California Sen. Kamala Harris, will become the first female vice president. She'll also become the nation's second Black candidate, following former President Barack Obama, to serve as president or vice president.

"This election is about so much more than [Biden] or me," Harris tweeted shortly after being declared vice president-elect. "It's about the soul of America and our willingness to fight for it. We have a lot of work ahead of us. Let's get started."

Biden's slim victory perhaps validates the central conceit of a presidential campaign that fellow Democrats often doubted: After nearly four divisive and drama-filled years of the Trump administration, voters would long for stability and a return to the status quo that Biden and his nearly five decades of federal government experience represented.

From the moment he launched his campaign in April 2019, Biden focused on what he called a "battle for the soul of our nation," arguing that Trump was a dangerous aberration in American political history — but an aberration that voters could course-correct.

The election was seen as a referendum on Trump's tenure, particularly how he had handled — or mishandled — the coronavirus pandemic.

And though the election was highly contested, Biden led Trump in polls for almost the entirety of what was, ultimately, a remarkably stable presidential race in an anything-but-stable year.

But for Biden, a career politician, this victory is a political comeback — a triumph that comes after a rocky start in this year's primaries and two previous failed attempts at the presidency years ago.

An early political triumph, then tragedy

Biden was born in Scranton, Pa., in 1942, and when he was young, his family moved to Claymont and then Wilmington, Del., as his father looked for steady work.

"The longest walk a parent can make is up a short flight of stairs to their child's bedroom to say, 'Honey I'm sorry, we have to move,' " Biden has often recalled.

Biden struggled, too, to overcome a severe childhood stutter. He learned to navigate it in part by memorizing and reciting the poems of William Butler Yeats and other Irish poets in his bedroom mirror.

Biden went to the University of Delaware, and then law school at Syracuse University, where he met his first wife, Neilia. They returned to Wilmington and started a family as Biden quickly established himself as a politician, winning a seat on the New Castle County Council, and then, in 1972, launching an improbable run for the U.S. Senate.

Biden wouldn't turn 30, the minimum age to serve as a senator, until after the election. He won in an upset and was set to enter the Senate as a rising Democratic star.

Then, Biden's life was shattered. Neilia and their three children — sons Hunter and Beau, and daughter Naomi — were hit by a truck while Biden was in Washington, D.C., setting up his new Senate office. Neilia and Naomi were killed, and Biden weighed resigning his seat before he was sworn in in order to care for his surviving children.

Majority Leader Mike Mansfield, D-Mont., helped persuade Biden to stay in the Senate. And Biden began a habit that would become a trademark of his life and political career: He commuted every single day between Wilmington and Washington, D.C., in order to spend as much time at home with his children as possible.

Biden married again, in 1977, to Jill Jacobs.

After two runs for president, the vice presidency

The Delaware senator made his mark in the chamber on the Judiciary and Foreign Relations committees, serving for long stints as chair or ranking member on both. Biden presided over several high-profile and contentious Supreme Court confirmation hearings, including Robert Bork's failed nomination and the hearings during which Anita Hill accused future Justice Clarence Thomas of sexual harassment.

Biden ran for president in 1988 and 2008. Both times were considered flops. He withdrew from the 1988 campaign before the Iowa caucuses in part because of a plagiarism scandal. In 2008, Biden carved out a niche during the debates as a foreign policy expert but finished well behind fellow Sens. Barack Obama and Hillary Clinton in Iowa, and quickly dropped out.

But Biden had made an impression on Obama during those debates. That summer, looking to compensate for his lack of foreign policy experience and his relative newness to Washington — and also looking to appeal to white voters who may have been skeptical of the first Black major-party presidential nominee — Obama tapped Biden as his running mate.

Biden headed several key policy efforts for the Obama administration, including the 2009 stimulus package that's credited with helping pull the economy out of a spiral toward a depression. Biden helped set the administration's foreign policy agenda and often acted as the more aloof Obama's emissary to Republican congressional leaders like Kentucky's Mitch McConnell. Biden and the Senate Republican leader crafted several budget compromises in the later years of the Obama administration.

When Obama signed the landmark Affordable Care Act in 2010, Biden punctuated the moment with a hot mic assessment that instantly became iconic in Democratic circles: "This," Biden whispered into the president's ear as they stood in the White House East Room, "is a big f****** deal."

Biden weighed another run for president in 2016, but it was clear many people in Obama's orbit, including the president himself, preferred Clinton as the party's next standard-bearer.

Another, devastating factor sealed Biden's decision not to run: Tragedy struck his family one more time as his son Beau, who had risen to become Delaware's attorney general, died of brain cancer in 2015.

A dramatic turn in South Carolina

By the time Biden decided to enter the presidential race this cycle, in April 2019, there were already some 20 other Democrats in the field.

But Biden entered the crowded primary as the clear front-runner, with strong name recognition and a simple message — he was running to "restore the soul of our nation." He spoke about morality, character and unity.

It was, to his critics on the left within his own party, the wrong message for this moment; it was optimistic when many Democrats were demoralized and angry.

Throughout the primaries, Biden spoke of bipartisanship when many Democrats were convinced that was an outdated political vision. Progressives thought of Biden as the out-of-touch elder statesman who didn't understand the modern Democratic Party.

They wanted sweeping systemic change; they wanted "Medicare For-All"; they wanted a wealth tax. And Biden seemed to offer only incremental solutions to their problems.

He was battered by his fellow Democrats during the primary debates for his orchestration of the 1994 crime bill and his work with segregationist senators.

And yet despite that record and the fact that he faced several Black opponents — including Harris, his eventual running mate — the polls showed Biden consistently had the support of Black voters. Some elder Black voters pointed to Biden's loyalty to Obama during their eight years in the White House. Others more specifically pointed to Biden's willingness to be "No. 2" to a Black man, something they said many white people wouldn't be willing to do.

Campaign aides routinely insisted there was no path to the Democratic nomination without the clear support of Black voters. And in their view, no candidate but Biden had support from that key demographic.

Still, the early primaries were rocky for him. He finished fourth in the Iowa caucuses, and fifth in the New Hampshire primaries. His fundraising slowed to a trickle.

New Hampshire was such a blow to his candidacy that his campaign hightailed it out of the state before the polls had closed. That night, Biden was instead in South Carolina, where he tried to reassure his supporters not to count him out.

"We just heard from the first two states," Biden said during a speech in Columbia, S.C. "Where I come from that's the opening bell, not the closing bell."

But at that time, Vermont Sen. Bernie Sanders appeared to be on his way to building an insurmountable lead in the primary's early states. Biden needed a decisive win in South Carolina to resurrect his fledgling campaign — and he got it. With the help of the endorsement of Rep. Jim Clyburn, the most influential Democratic politician in the state, Biden won South Carolina by roughly 30 points.

It was the conclusive victory he needed to head into Super Tuesday, the single most consequential day in the Democratic primary process, in which more than a third of all delegates were at stake. But Biden was still without the campaign infrastructure, grassroots support and the fundraising dollars that some of his rivals boasted.

And so perhaps just as influential as the South Carolina result itself was the decision by a number of Biden's rivals to quickly coalesce behind him. On the eve of Super Tuesday, three of Biden's former opponents — former South Bend, Ind., Mayor Pete Buttigieg, Minnesota Sen. Amy Klobuchar and former Texas Rep. Beto O'Rourke — endorsed him in quick succession.

That day was critical in swiftly reshaping the narrative of the primary campaign.

The end result was that Biden scored huge victories on Super Tuesday. Shortly after, the Democratic contest became a two-man race between Biden and Sanders.

But before that battle could substantively get underway, the country was facing a new crisis: The coronavirus was threatening to close schools, shutter businesses and hospitalize vast numbers of Americans.

On March 10, as voters cast ballots in Michigan and five other states, Biden and Sanders both abruptly canceled primary night rallies because of public health concerns. The campaign trail would never return to normal, and Biden would at times struggle to adapt to a new remote-only platform.

Biden won Michigan in a rout, and the primary was effectively over.

In countless interviews, voters — even some on the more progressive end of the party — said they ultimately opted for Biden because they thought he had the best chance of defeating Trump, regardless of whether they agreed with all of his ideas.

By early April, Sanders decided to end his own campaign. Unlike in 2016, he enthusiastically endorsed and worked with his rival to unify progressives against Trump.

Taking on Trump

Biden ran his primary campaign in much the same way that he would go on to wage his general election bid — with an appeal to unity and healing.

But the coronavirus pandemic brought traditional campaigning to a standstill. For months, Biden was stuck at home in Wilmington, Del., trying to fight an Internet war against a president known for his social media savviness.

But as the pandemic turned into an economic recession, coupled with a summer of racial protest, the November election increasingly turned into a referendum on Trump's leadership. Polls showed voters increasingly losing confidence in how the president was handling the pandemic and race relations. And the Biden campaign sought to fill that leadership void by focusing on competence and empathy.

"Today in America, it's hard to keep faith that justice is at hand. I know that. You know that," Biden said in a June 2 speech in Philadelphia, the day after Trump responded to nationwide protests by marching through a Washington, D.C., park that had been cleared of protesters by force so that he could appear in front of the press at a damaged church. "The pain is raw. The pain is real. A president of the United States must be part of the solution, not the problem."

When Biden cautiously returned to the campaign trail after those remarks, he did so in eerily empty settings. Biden would often give speeches to empty rooms of socially-distanced reporters. Over time, his campaign filled venues with a few dozen supporters at a time, eventually building up to drive-in rallies. The sometimes-awkward scenes were efforts to prioritize safety and to signal to voters that Biden — who was regularly seen wearing a mask — took public health seriously.

Trump, on the other hand, began to ignore the advice of his own public health advisers and held massive in-person rallies — most open-air, some indoors — with supporters — many without masks — crowded together.

As the U.S. death toll from the pandemic climbed, eventually surpassing 200,000 people, many parents entered a new school year juggling the demands of working from home while monitoring virtual classes. And yet despite the instability, the polls seemed to suggest a remarkably stagnant race. Throughout the summer and into the fall, Biden retained a consistent lead in most national polls.

And after struggling to raise money in the primary, Biden's team started collecting huge sums, often from virtual fundraisers. Just in the months of August and September, the campaign and joint Democratic efforts raised nearly $750 million, smashing records. That money gave the campaign the resources to invest and try to compete in traditionally Republican states like Texas and Georgia.

The race's most notable stretch came near the end of September, when Biden and Trump met face to face for their first debate, and the president made the event nearly unwatchable with constant interruptions. Then, a couple of days later, news broke that the president had been diagnosed with the coronavirus. He was soon hospitalized for treatment.

It was an unpredictable October surprise, and yet Trump acted as if it didn't matter. He was quickly back on the campaign trail, holding his trademark rallies and boasting that he felt better than he did 20 years ago.

He continued to defend his administration's response to the virus, citing his decision to ban some travel from China and his efforts to boost therapeutics and vaccines.

What's on the Biden agenda

In the final days of the race, Trump dismissed the pandemic even more bluntly than before — as cases soared to new records in key electoral states like Wisconsin.

Biden, on the other hand, promised to immediately marshal the resources of the federal government toward tackling the pandemic. He has promised that his administration will centralize decision-making on distributing testing and personal protective equipment. He will push for universal mask usage and has urged Congress to pass a substantial coronavirus relief package in the first weeks of his administration.

The longtime foreign policy expert has also vowed to repair the international alliances that have been frayed by four years of an isolationist, treaty-busting Trump administration, beginning with a reentry into the Paris climate accords.(The U.S. withdrawal from the accord actually became official the day after Election Day.)

Over the course of the campaign, Biden embraced many of the more progressive policy goals of his onetime primary rivals. He'll enter office vowing an agenda inspired by the transformative New Deal of Franklin Delano Roosevelt.

Biden wants to retool the Affordable Care Act by adding a public, government-run option; invest $2 trillion in green energy and transform the country's energy production to almost entirely renewable sources over the next 15 years; and make massive investments in education and child care, including universal pre-kindergarten and tuition-free public college for middle- and lower-income students.

But the broad scope of Biden's progressive agenda took a serious blow with Democratic struggles to flip Senate seats this election. As of the AP race call for Biden, control of the upper chamber remained in doubt.

Regardless, throughout his entire campaign, Biden largely emphasized tone and style over policy. He began and ended his campaign promising to "restore the soul of the nation" and repeatedly vowed in its closing days to govern with all Americans in mind, not just the ones who voted for him.

"We must seek not to tear each other apart, but to come together," Biden said in a speech in Gettysburg, Pa., last month. "What we need in America is leadership that seeks to deescalate tension, to open lines of communication, and to bring us together."

As Obama's vice president, Biden saw firsthand that unifying messages and aggressive policy agendas are difficult to make coexist — especially in a divided government.

Now, elected president after a lifetime of government experience, in the wake of a turbulent and divisive administration, and amid an unprecedented global crisis, Biden will get his chance to try to accomplish both those ambitious goals.

Copyright NPR 2021.