Democratic candidate Joe Biden issued a "colossal" mistake during the Democratic debate Wednesday and he was immediately ridiculed on social media and on the debate stage.

The brutal misstep happened when Sen. Cory Booker (D-N.J.) was challenging the former vice president on his support in the black community.

"I have more people supporting me in the black community that have announced for me, because they know me. They know who I am," said Biden.

"Three former chairs of the black caucus. The only African American woman to ever be elected to the United States Senate. A whole range of people!" he added.

But not only was Biden wrong about there only being one black female Senator, but he was completely ignoring that Sen. Kamala Harris (D-Calif.), the second black female elected to the Senate, was standing on the debate stage next to him.

"That's not true!" laughed Booker, laughing.

"Nope. That's not true," laughed Harris. "The other one is here!"

The audience burst out in laughter at Biden's brazen gaffe. He was also brutally mocked online by both left and right for the mistake:

MSNBC host Lawrence O'Donnell called it a "colossal" gaffe and said it was as bad a mistake as Biden could have made on the debate stage.

However, as awkward as the moment was, Biden was right in claiming he has a momental lead among all of the presidential candidates in the black community.

Biden's campaign didn't help him much when they prematurely sent out a post-debate email hours before the debate even started.

Here's the video of the awkward mistake: