Berman has been in Congress 30 years, while Sherman has been there 16 years. But they are forced to compete for the same congressional seat because of redistricting.
The Berman campaign posted the incident on YouTube. In the footage, 57-year-old Sherman lunges forward and seizes 71-year-old Berman by the shoulder, yanks him toward his chest and shouts, "You want to get into this?" The two held a brief stare-down, with their faces inches from each other.
A sheriff's deputy felt it necessary to come between the two veteran congressmen and lower the tension.
Sherman refused to characterize what happened as a confrontation.
"He came on over pretty angry at me on a particular issue, called me a liar, put his face into mine. And then I put my arm around him, which I should not have done," he said.
Berman has a different take on what happened, saying Sherman was unhinged and that he just snapped.
"You think this was a friendly pat? This was a guy who was grabbing me around the shoulders," Berman said. "No one has ever tried to physically intimidate me, grab me, threaten me."
Moments earlier, during a dispute on an immigration-related bill, Berman, the ranking Democrat on the Foreign Affairs Committee, stepped close to Sherman on the stage, who told his colleague loudly, "Get out of my face."
After the incident, the two congressmen went back to the debate and finished fairly calmly. The students got a rare and unusual look at just how tense politics can get.