Whitman, a Republican and the former CEO of eBay, was finishing her remarks when a man sitting in the front row stood up and began shouting.
"What are you hiding?" he yelled. "You're looking like Arnold [Schwarzenegger] in a dress."
Christie rose from his seat behind Whitman and confronted the man.
"You want to yell-yell at me, but don't give her a hard time," Christie said as he came face-to-face with the man.
"It's people who raise their voices and yell and scream like you that are dividing this country, we're here to bring this country together-not to divide it," Christie added.
Christie was in California campaigning for Whitman, who is facing state attorney general and former Gov, Jerry Brown in a heated race to replace Gov. Arnold Schwarzenegger, who is term-limited. A Field Poll released Thursday indicates the two are deadlocked, each with 41 percent support among likely voters. Eighteen percent remain undecided.