It's a rhetorical trick that goes back centuries. People like Hitler, Mussolini, Malcolm X, and many that proceeded them in history know how to work up a crowd. A crowd is a mindless thing, only as intelligent as the lowest IQ among them. An effective speaker like that will begin speaking rather slowly and distinctly, making points, maybe a mild joke, and ever so slowly will pick up the pace and the volume, until 30 minutes into the speech they are yelling just like AOC here, whipping the crowd into a frenzy.

At this point in her speech she could have been yelling, "Go out there and kill babies!!" and they would have done it.

I've noticed the same rhetorical pattern in some preachers in different religions. By the time the sermon is finished, people are swept up into a emotional state that some take to be a "religious experience." It's mostly psychology.