What caused Andrew Breitbart's now infamous meltdown at CPAC?

Many commenters suggested that Breitbart was drunk, and this video seems to suggest just that. Listen as Breitbart is preparing to go confront the crowd, someone off-camera says that it would look bad to do so with a glass of wine in his hand.

“So what? We’re allowed to drink wine in America!” Breitbart says. A moment later, there’s the sound of breaking glass.

Then he heads outside towards to protesters, and Breitbart jumps out from behind some shrubs and decides to take it upon himself to take the occupiers to task, and starts shouting "Behave yourself! Behave yourself! Behave yourself!" Before security escorts him away he continues screaming "Behave yourself! You're freaks! You're freaks and animals! Stop raping the people! You freaks! Stop raping the people!"

Was he drunk? You decide. He certainly was disheveled, wild-eyed and vitriolic...oh, wait.

Here's the video of that epic rant again, too.