Jesse "The Body" Ventura came thiiiiiiiiis close to beating the living crap out of comedian Jim Norton on a live radio show early this morning -- over a political conversation that went worse than the Gulf of Tonkin.

It all went down on the Opie and Anthony radio show, when Ventura -- a former wrestling champ turned politician -- arrived for an in-studio interview. Ventura was explaining why he doesn't trust the U.S. government -- when Norton, a regular on the radio show, began arguing with him.

After an intense back-and-forth, Ventura decided to leave and as he patted Norton on the shoulder on the way out -- Norton said, "Thanks for touching me with your f*cking stupid riff-raff Rocky Horror hairdo."

Ventura turned and stared Norton down -- until Norton proclaimed, "You're bigger than me and stronger than me ... so what?! You want to beat me up? Go ahead."

Ventura, who served in an elite Navy unit during the Vietnam years, kept his composure and eventually walked away.