Michigan allows it. He will have to wait until he is 16.
http://michiganlegalhelp.org/self-help-tools/individual-rights/emancipation-becoming-adult-age-18
Read through the information. Emancipation requires a demonstration that the child is self-supporting, typically must be agreed to by the parent (unless the child is able to demonstrate that the parent has not contributed to their financial upkeep). Not something that a kid can do just because they don't happen to like who they were born to. And for good reason. Emancipating a child who is not truly capable of being independent simply transfers their dependence--sometimes to the state, but sadly also opens the possibility of being vulnerable to exploitation from others willing to provide (traffickers and the like).
Frankly I find the whole notion--being articulated by a few--that children should be empowered to dump their parents at will speaks to a shockingly permissive view of child-rearing. Makes me wonder if such advocates have children and are raising their own children in such a permissive atmosphere, or are simply applying such views to other people's children.