WASHINGTON >> President Joe Biden declared on Saturday that white supremacy is “the most dangerous terrorist threat to our homeland” and warned a predominantly Black audience that “sinister forces” embraced by his predecessor and putative challenger are trying to reverse generations of racial progress in America.

Biden never named former President Donald Trump in his sometimes stark commencement address to the graduating class of Howard University, the nation’s most prestigious historically Black college. He alluded, however, to Trump’s past statements to link him to racist elements in American society and suggest that the presidential campaign that has just gotten underway will determine whether justice will prevail over hate, fear and violence.

“There are those who demonize and pit people against one another,” Biden said. “And there are those who will do anything and everything, no matter how desperate or immoral, to hold onto power. That’s never going to be an easy battle. But I know this — the oldest, most sinister forces may believe they’ll determine America’s future.

“But they are wrong. We will determine America’s future. You will determine America’s future.”

Wearing blue and white academic robes, the president sought to enlist the young graduates in what he presented as the cause of this moment. He cited the killing of George Floyd by a police officer in 2020, which touched off widespread protests against police brutality, and expressed empathy with Black drivers who are fearful when they are pulled over by officers.

“Fearless progress toward justice often meets ferocious pushback from the oldest and most sinister of forces,” he said. “That’s because hate never goes away. I thought when I graduated that we could defeat hate. But it never goes away.”

Likewise, Biden said that “after the election and reelection of the first Black American president, I had hoped the fear and violence and hate was significantly losing ground.”

He discovered otherwise, he said, when neo-Nazis and white supremacists clashed with counterprotesters in Charlottesville, Va., in August 2017, and he recounted Trump’s reaction.

“What did you hear?” he asked. “That famous quote: ‘There are very fine people on both sides.’ That’s when I knew, and I’m not joking, that’s when I knew I had to stay engaged and get back into public life.”

Trump’s supporters have said his line has been distorted and note that he did at one point condemn neo-Nazis. But as he has opened a campaign to recapture the presidency, Trump has more openly embraced racist and extremist elements in American life. Last winter, he hosted for dinner the rap artist Ye, who has made antisemitic statements, and Nick Fuentes, a prominent white supremacist who attended the far-right Charlottesville rally.

The choice of Howard offered Biden an opportunity to shore up support in the most loyal constituency in the Democratic Party.

While polls show continued strong support for Biden among Black voters, political analysts and party strategists have expressed concern about an enthusiasm gap that could complicate prospects for the president, who needs high turnout from his base.

Biden has been stymied on goals such as cracking down on police brutality and bolstering voting rights.

He did sign an executive order on federal law enforcement last year, although crucial pieces of the order have not been implemented.

Many supporters say he has fallen short on his pledge to make systemic changes to the criminal justice system.