President Donald Trump mocked Joe Biden after the former vice president launched his campaign for the Democratic presidential nomination in 2020.

In a video in which he criticized Trump for his comment about the 2017 white supremacist rally in Charlottesville, Va., that turned deadly, Biden made his long-expected announcement.

“With those words, the president of the United States assigned a moral equivalence between those spreading hate and those with the courage to stand against it,” Biden said. “And in that moment, I knew the threat to this nation was unlike any I’d ever seen in my lifetime.”

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“If we give Donald Trump eight years in the White House he will forever and fundamentally alter the character of this nation,” Biden warned.

The former vice president kicks off his campaigning in Pennsylvania, a state Trump barely won against Hillary Clinton.

Biden enters the Democratic race as the leading candidate, and Republicans see him as Trump’s toughest challenger. He could face challenges in securing the nomination and faces a tough race in a crowded field of candidates and in an environment where party activists are seeking younger and more progressive nominees.

Last week, Trump tweeted that he believed the race would be between Biden and Sen. Bernie Sanders and he looked forward to whoever it would be.