I'm not the poster, but here's what I envision they're suggesting. The "political type" is somebody who approaches a conversation not out of a good faith desire to come to a mutual understanding, or to better communicate things the conversant may not be aware of, but simply as a transaction that they can use to further some agenda (or, alternately, they view the conversation as a trap they must successfully navigate to avoid having their agenda impeded).

This is either somebody who is already convinced they are right or somebody who doesn't care about what is right. The latter is particularly dangerous - these people are only interested in increasing their esteem within a group and in reducing their "opponent's" esteem. The outcome of the conversation is totally irrelevant to them, except insomuch as it furthers those objectives by scoring "points."