Joe Biden put his foot in mouth before the debate even started
Joe Biden -- Screenshot

Vice President Joe Biden is known for being particularly gaffe-prone, and just seconds after he took center stage at CNN's Democratic debate Wednesday night, he put his foot in his mouth.

After Sen. Kamala Harris of California joined him onstage, Biden could be heard saying "Go easy on me, kid" as they shook hands. It was clearly a reference to her criticisms of him at the last debate, but the appearance of calling a grown woman of color "kid" was particularly jarring.

Harris, many observers noted, is 54 years old.

Watch the clip below: