That's what I use it for, political philosophy and theory. There is a danger of overly-specific tagging, but in the case of #politics we have an instance of extreme generalization that is actually harmful. We have to strike a balance and clearly we are too far towards the "general" end of the spectrum, so I am advocating a move towards specificity in this case. In your particular example, I'd use something like #uspolitics #maine, or perhaps just #maine and some other relevant tag. See #texas for some analogous examples. If someone wanted to community-tag it #mepolitics or start using #mepolitics on their own posts for whatever reason, that's their perogative.when would instances of "general" politics occur? In articles on political theory?
Also, if we get too specific with tags, then what is the point? So, let's say that #uspolitics is used. What's stopping someone from saying, "hang on a sec, that's not U.S. politics, that's Maine politics. Use the #mepolitics tag."