Arise is a verb that means to get up, maybe to stand or get out of bed, like when you arise in the morning to get ready for the day.
The verb arise can apply to people when they get up but it can also apply to issues or situations that come up, like problems that arise when a leader takes away people's rights. What happens next? People might arise, meaning they rebel, protesting the leader's actions, maybe even declaring that they are no longer under his or her rule. If this happens, a new political party will likely arise, meaning "come into existence."