It’s a variety of purposes, but in this type of social media space it’s usually to push specific agendas, often political. The accounts will often engage primarily by “reposting” comments to give a profile appearance that looks like a person. Then they engage in manipulations of conversation in specific ways. For instance, they might play “devil’s advocate” in left-leaning political spaces to plant certain view points. One of the quirks of the human brain is that we tend to believe things we read over and over, regardless of the source, because volume breeds validity. It’s a part of being a social species and being hardwired to be part of the herd.

If you hang out on social media and you read over and over, from multiple posts, that someone is a war hawk, that becomes part of your “sense” of them. Often these conversations are subtly shifted just by posting opinions with little to no substantiation. Your brain starts to think “wow, there are a lot of people saying that guy is a war hawk” and, since we’re wired to conform to the group, you wrap that into your total opinion of the person. You’ll also see just general “shaping” posts without a clear angle where the intent is to shape your perception of a public figure negatively or positively.

Think about your opinion of a public figure. Just your sense of who they are. Do you actually know facts that guide what you feel, or do you just have a sense of them based on all the things you “know” about them?