Joe Biden formally launched his bid for the presidency Thursday morning, bringing an end to months of speculation on whether he would make a third run for the White House.

The former vice president and longtime U.S. senator unsuccessfully ran for the party's nomination in 1988 and 2008, but is now seen by some pundits as the Democrats' best chance to defeat President Trump in 2020. 

"The core values of this nation, our standing in the world, our very democracy, everything that has made America -- America -- is at stake. That’s why today I’m announcing my candidacy for president of the United States," Biden said in a video to launch his campaign. 

Biden recalled Trump's "very fine people on both sides" remark following a white supremacist rally in Charlottesville, Virginia, in 2017.

"In that moment I knew the threat to this nation was unlike any I had ever seen in my lifetime," he said.

Responding on "America's Newsroom," Fox News politics editor Chris Stirewalt said Biden's entry into the race ends the "fluffy pink cloud of a Democratic primary," where the candidates have been avoiding attacking each other. 

"They're gonna have to hit him. ... We'll soon find out whether or not he can hit back," he explained, arguing that the other candidates cannot let Biden "operate in [a] separate space as the grand old man of the party."

Watch the full analysis above.

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