Well do you? A lot of people would say no but I don't think that to be true. You do have to like someone to hate someone and do you know why? Because of the way it feels... you have to be interested to hate someone and you'll have to express more "like" to continue to hate someone.
Almost like love really... but there is a thin line between love and hate. It's very easy to get mixed up; first you like someone then you hate someone and vice versa! I think that's a reason why some people would agree with me, because they just happen to feel it's right! Also there is the fact that one form of hate is jealousy and we all know where that comes from: Envy. = Wanting.= Like.
My explanation is this: A lot of emotions that we have, that we feel; mixes like a cocktail (weird explanation I know)! A lot of them are just higher forms of simpler emotions ex. like = love, hate= like+anger+pride+dislike. Hating someone, you will have an interest to hate them and you're angry with them and your pride is keeping you from letting it go while you dislike that person. All emotions are connected with each other; they walk hand and hand with one another because they all originate from love.
The reason I believe you have to like someone to hate someone the most is because we were all created in God's image; including our emotions. They all lead back to God and God is love.