Former Vice President Joe Biden made it official Thursday morning, finally announcing his candidacy for president in a video, saying Democracy “is at Stake,” and incumbent President Donald Trump immediately went on the offensive.

Biden is now one of 20 hopefuls in a crowded field for the Democratic primary, where he will likely be the favorite as the most centrist and business-friendly among a bevy of far-left candidates led by Sen. Bernie Sanders, I-Vt.

“The core values of this nation, our standing in the world, our very democracy, everything that has made America America is at stake,” he said in a video posted to Facebook and Twitter on Thursday morning. “That’s why today I’m announcing my candidacy for president of the United States.”

Biden’s announcement comes three years after he declined to run due to his family grieving over the loss of his oldest son, former Delaware Attorney General Beau Biden, who died from brain cancer at just 46 years old.

Biden also went right at Trump in his announcement, saying another four years with him in office will “fundamentally alter the character of this nation.”

“We are in the battle for the soul of this nation,” Biden said. “I believe history will look back on four years of this president and all he embraces as an aberrant moment in time.

“But if we give Donald Trump eight years in the White House, he will forever and fundamentally alter the character of this nation, who we are, and I cannot stand by and watch that happen.”

And much like Trump, who has been accused of sexual misconduct by a number of women, Biden recently faced accusations about his own behavior after four women came forward with claims he had hugged, kissed or rubbed noses with them without their permission.

The allegations reportedly caused Biden to lose some ground to Sanders and South Bend, Indiana, Mayor Pete Buttigieg in some state polls.

Of course, the allegations against Trump ended up not mattering much as he was still able to win the presidency over Hillary Clinton, and he maintains the women all were lying.

Biden also has denied the allegations against him.

One of the best predictive polling sites, FiveThirtyEight, which gave Trump a 28.6% chance to win in 2016, laid out its case for why Biden is the front-runner.

Biden has particular appeal among more moderate Democrats, particularly among the working class — where Trump was able to muscle in and take some former Barack Obama voters away from Clinton in the 2016 election. Biden is particularly popular in his home state of Pennsylvania, a swing state that Trump won in 2016. He also could be a force in Wisconsin and Michigan, two important states for Trump’s reelection chances.

In all, Trump topped Clinton by 0.7% in Wisconsin, 0.3% in Michigan and 0.7% in Pennsylvania. These three states will likely play a critical role in electing the next president.

But first he has to fend off a large group of challengers in a Democratic party that appears to be swinging further to the left with the rise of Sanders and people like Rep. Alexandria Ocasio-Cortez, two Democratic Socialists.

Ultimately, the primary will be a gauge of exactly how far left the party as a whole has swung.