I propose a new badge of 'Controversial' for comments, answers and questions which have both upvotes and downvotes (perhaps 10 up and 8 down).
This isn't in our power. The badge-system is the same for all Stackexchange sites. There are no site-specific badges as far as I know. So if you want a new badge, you need to lobby for it on the general meta-stackexchange.
But even if we could add such a badge, I don't think we should. The purpose of badges is to encourage people to participate constructively to the site. They should reinforce the kinds of behaviors we want to see.
But controversy isn't what we want on this website. To the contrary. We want people to ask questions which honestly look for knowledge about politics and answers which explain from a neutral and objective viewpoint, untainted from any agenda and without partisan rhetoric.
But the best way to get this badge would be to do the exact opposite: Write a troll-post which panders to one political faction while attacking the other, and you will get a voting-war of opponents and supporters. Such posts are very counter-productive for the site. They polarize the community into political factions and they distract us from what we actually want to do here: Not building yet another political discussion forum but building a knowledge-base with information about politics.