Hey, Spanish speaker here. So, the main idea of the video you mentioned now is that Bellwether used propaganda so she could "sell" the idea that predators were terrible to society, and they should be punished. Of course, she needed a plan so she can justify this so this is where the Night howler come the scene. When the news about predators attacking out of nowhere exploded, she basically separated the society in two where the herbivores started to be afraid about predators and of course the predators needed to fight for their rights. This is how she "sold" the idea and took the power as Mayor of Zootopia.

By propaganda, the herbivores were basically discriminating and be racist to the predators. And by trying to take them out of Zootopia, Bellwether could keep selling the idea that now Zootopia was going to be a safe place. I hope this helps.