if he has no potential whatsoever, start moving away from him (still talk to him, just don't become close friends or stay close friends)
if he has potential, take him with you as you become more popular. teach him stuff in a playful manner, so you don't seem so serious. e.g. if his posture is bad, which is the case with most chumps, say "man, you look like an old man with a sore back walking like that". then you can tell him that working on his back in the gym will make it easy to have good posture.
but, like jsh said, stick up for him if you can if he gets made fun of, no matter what he's like. that will get you respect on top of making you feel good, cuz you're becoming more of a leader. you don't let your troops get the shyt kicked out of them
it's useful to have someone who can become a dj with you, because they will always be there for you and can give you advice on how you act, what you need to work on etc