I've seen political stories flagged pretty quickly during normal HN usage, but rarely comment threads.
I assume putting the "flag" button one click away is to prevent people using it as a down vote when arguing, but it definitely means that I never flag comments, only stories. And comments are the place where "politicalness" really has the damaging effects.
I wonder if there might be either an opt-in to keep it zero clicks away, or maybe over a certain amount of karma it is visible, or some other compromise so that proper comment flagging is more widespread.