Agenda voting is the practice of subverting the democratic process in order to further one's own agenda. It can be summarized as exercising one's democratic rights in such a way as to further a particular belief, instead of in the way necessary for the democracy to properly function. This is usually intended to exaggerate the representation (and power) of an individual or group within the democracy.

Example: You are given voting rights in everything, and a loose set of guidelines, which for this hypothetical example, we will summarize as: if the writeup is intelligent and appropriate to the title of it's node, you should vote positively. If it is not, vote negatively.

You are stridently anti-abortion. You encounter a node titled "abortion should be legal" with an intelligent and carefully written writeup attached. You downvote that writeup, not because you believe it is unintelligent or inappropriate to its node's title, but because you are opposed to the ideology it expresses.