TEHRAN - Former U.S. Vice President Joe Biden formally joined the crowded Democratic presidential contest, declaring the “soul of this nation” at stake if President Donald Trump wins re-election.

In a video posted on Twitter, Biden focused on the 2017 deadly clash between white supremacists and counterprotesters in Charlottesville, Virginia. Biden noted Trump’s comments that there were some “very fine people” on both sides of the violent encounter, which left one woman dead.

“We are in the battle for the soul of this nation,” Biden said. “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.”

According to AP, the 76-year-old Biden becomes an instant front-runner alongside Vermont Sen. Bernie Sanders, who is leading many polls and has proved to be a successful fundraiser. Biden has legislative and international experience that is unmatched in the Democratic field, and he is among the best-known faces in U.S. politics.

He quickly racked up endorsements Thursday, becoming the first Democrat running for president with the backing of more than one U.S. senator. Still, Biden must compete in a field that now spans at least 20 Democrats and has been celebrated for its racial and gender diversity.

As an older white man with occasionally centrist views, Biden has to prove he’s not out of step with his party. He’s yet to outline his positions on the issues defining the 2020 Democratic primary, most notably “Medicare for All,” the universal health care plan authored by Sanders that has been adopted by virtually the entire Democratic field.