My Guess

Opposites attract doesn't apply to politics.

And for the most part, I think the phrase is wrong. I suppose it's right to a certain extent, because if you were completely like someone you would probably just annoy the fuck out of each other. On the other hand, being completely different would mean you have nothing in common, and that would also suck. Being similar in some areas has it's bonuses, for instance, what kind of movies you like, video games, food, etc. Being completely different would make living together with someone else pretty hard.