This is not an area in which I have precise expertise, so I'm not going to take long to say it.
The most effective way that this can happen, as I've seen it, is by inserting into the ecosystem ideas about what political candidates would do or what parties would do. Then it allows individuals who are interested in politics and like to talk about it to spread those ideas. Think about it as an infection and a virus that spreads. That's an effective mental model for understanding how the CCP wants to influence voters' views during elections.