Joe Biden is officially running for reelection. 

The Democratic president announced in a video Tuesday that he is entering the race for the White House.  

"Every generation has a moment where they have had to stand up for democracy," Biden said in his announcement. "To stand up for their fundamental freedoms. I believe this is ours."

"That’s why I’m running for reelection as President of the United States," Biden added. "Join us. Let’s finish the job."

Biden, 80, has said since shortly after taking office that he planned to seek a second term, but with no major challengers for the Democratic nomination, there had been little urgency to formally declare his candidacy. 

His announcement comes four years to the day that he jumped in the 2020 race, which culminated in him defeating Republican incumbent Donald Trump. This marks Biden’s fifth presidential run, although his three campaigns before serving as Barack Obama’s vice president gained little traction.

Vice President Kamala Harris will again be Biden's running mate.

The campaign's leadership group includes key congressional allies like Reps. Jim Clyburn, an influential South Carolina lawmaker who helped Biden's fledgling campaign in the 2020 primary, Lisa Blunt-Rochester, D-Del., and Veronica Escobar, D-Texas, as well as Hollywood mogul Jeffrey Katzenberg and Michigan Gov. Gretchen Whitmer, a rising star in the Democratic Party. Julie Chavez Rodriguez will serve as Biden's campaign manager. 

Biden’s announcement sets up a potential rematch against Trump, who announced in November he is running again and is leading in the polls for the GOP nomination.

Biden beat out a vast field of Democrats four years ago but figures to have any easier path to the party nomination this time. The only two other Democrats to declare their candidacies to date are self-help author Marianne Williamson and environmental lawyer and anti-vaccine advocate Robert F. Kennedy Jr. Neither has any political experience, and both are widely considered long shots.

Biden has achieved a handful of major legislative victories as president, including signing bills to provide Americans with relief from the COVID-19 pandemic, improve the nation’s infrastructure, make investments to combat climate change and lower people’s health care costs, and boost domestic microchip manufacturing.

The country also has enjoyed a decades-low unemployment rate – 3.5% last month – under Biden, and the president has repeatedly touted his role in coordinating support from other nations for Ukraine in its war against Russia.

“This is a president who has a record that is unmatched in a first term,” said Democratic strategist and SiriusXM radio host Ameshia Cross. 

“This is a president who has a lot to stand on," said Cross. "And I think we're going to see him and his surrogates go across the country touting that message, showcasing what it means in the states, and quite frankly, really hitting home on the levels of achievement that are there and, quite frankly, what the detriment would be should those things be upended.”

Biden kicked off his campaign by trying to make the case that he’s working to protect Americans’ freedoms while Republicans aligned with Trump are working to take some away.

“Personal freedom is fundamental to who we are as Americans,” the president said in his video. “That’s been the work of my first term, to fight for our democracy, to protect our rights, to make sure that everyone in this country is treated equally and that everyone is given a fair shot at making it.”

While showing images from the Jan. 6, 2021, Capitol insurrection and last year's abortion protests, Biden said “MAGA extremists” support cutting Social Security, reducing taxes on the wealthy, dictating what health decisions women can make, banning books, telling people who they can love and restricting voting.

“When I ran for president four years ago, I said we're in a battle for the soul of America. And we still are,” Biden added. “The question we're facing is whether in the years ahead we have more freedom or less freedom, more rights or fewer. I know what I want.”

Republicans have been quick to attack Biden on the United States’ messy withdrawal from the Afghanistan war, the trillions of dollars his signature legislative victories have cost, the country’s stubbornly high inflation and the nation’s security at the Southwest border, which they view as weak. 

Biden, like Trump, also has come under fire for having classified documents at his home and office from his time as vice president and senator. 

Biden’s job approval rating, according to Gallup’s monthly survey, is 40% -- near the lowest point of his presidency. 

Eighty-seven percent of Democrats approve of his work, but just 35% of independents and 3% of Republicans do.

An Associated Press-NORC Center for Public Affairs Research poll published Friday found that just 26% of Americans – and 47% of Democrats – say they want Biden to run again. But 81% of Democrats said they would probably support him in a general election if he were the party’s nominee.

On his inauguration day, Biden was already the oldest president to hold office. He would be 86 at the conclusion of a second term. 

With his age comes concerns about his fitness for office. According to a Harvard CAPS-Harris Poll released last week, 56% of voters surveyed said they have doubts about Biden’s capacity to do the job, and 63% said they are unsure if Biden would complete another full term if he were reelected.

Liz Mair, a Republican strategist, said she expects Republican candidates to attack Biden’s age and competency and cast his administration as being extreme. 

“I think that there's a pretty big sense that people have across the country that if they go and they check the box for Biden, they're not really voting for Joe Biden to run the country; they're voting for whoever Joe Biden has as his staff to run the country,” Mair said. “And maybe they're OK with that; maybe they're not.

“While Biden himself has always been a somewhat moderate Democrat – although I think less moderate than a lot of us thought – his staff have been extremely leftist,” she added. 

Republican presidential candidate Vivek Ramaswamy made that claim in a tweet Monday.

“The biggest farce in American politics is the claim that @JoeBiden is declaring his candidacy for U.S. President tomorrow,” Ramaswamy wrote. “He’s not really. It’s the managerial class using its compliant puppet to advance its own agenda.”

Recent polls have been mixed on a hypothetical rematch between Biden and Trump. A Yahoo News-YouGov poll last week had Biden with a four-point lead over Trump (46%-42%), while the Harvard CAPS-Harris survey had Trump up 45%-40%.

Mair said she thinks the criminal investigations into Trump over allegedly falsifying business records to hide hush money payments made to an adult film actress, trying to overturn the 2020 presidential election and allegedly mishandling classified documents will likely be too much for Trump to overcome if he faces Biden.

“When you look at the proportion of the electorate that now don't affiliate with either party and explicitly affiliate at independent, I mean, you just don't have enough people who are committed Republicans to overlook that kind of stuff, I don't think,” she said.

Cross said Biden should benefit from having defeated Trump before and the former president largely sticking to his past approach, as well as concerns about Trump following the Jan. 6, 2021, Capitol insurrection and the investigations involving him.

“We know what he's saying when he's going across the country at his fundraisers,” she said. “We know what he's tweeting out on Truth Social. Not a lot has changed for former President Trump. Neither has it for his base,” she said.

In a statement about Biden’s announcement, Trump said Biden had done more damage to the nation in four years than the five worst presidents in American history combined. Trump attacked him on spending, inflation, energy, the Russia-Ukraine war, the U.S. withdrawal from Afghanistan and more.

Trump also, without evidence, called Biden “the most corrupt president in American history,” adding, “Nobody can believe what’s going on, with again no retribution whatsoever.”

“With such a calamitous and failed presidency, it is almost inconceivable that Biden would even think of running for reelection,” said Trump, who continued to falsely claim the 2020 presidential election was rigged.

Asa Hutchinson, a former Arkansas governor who is running for the Republican nomination, said in an interview with CNN he was “disappointed” in Biden’s messaging in his launch video. 

“The president really focused on the past more and some of the divisions,” Hutchinson said. “I would hope and would think that he would be talking about the economy and talking about America's position in the world and strength.”

Kennedy said in a tweet Tuesday he has known and liked Biden for many years, “but we differ profoundly on fundamental issues such as corporate influence in government, censorship, civil liberties, poverty, corruption, and war policy, among others.”

Former President Barack Obama, whom Biden served under as vice president from 2009-17, posted on Twitter: "Proud of all that @JoeBiden and his administration have accomplished these last few years. He’s delivered for the American people — and he’ll continue to do so once he’s re-elected."