What's "have on one's side" mean? Is this a phrasal verb?

Native speaker’s answer
Rebecca
It's not quite a phrasal verb, but it is a common phrase! To be "on someone's side" means to support someone's opinion, actions, or position and to be loyal to them. So the line "have on one's side" means that someone supports someone's opinion or stance. Or rather, here, "everybody" supposedly supported this person's position or actions. Ex: She's on the opposition's side, not our side. Ex: I thought you'd always be on my side, but I guess I was wrong. Ex: We have Charles on our side. He'll vouch for us.