It will depend on each individual state and their requirements and restrictions for gaining residency. Some states it is very easy, while in others it is VERY difficult. Many have clauses that state if you are there attending college/professional school before you are a resident you will be denied residency, period, because your interest in the state is purely educational. Others want to know how much capital is invested in the state and how much physical property is located there and what not (yes, they send out residency Nazi's to check on all of this). With state budgets in the drain in most of the 50 states I have a feeling that more and more will adopt a policy of the latter than the former, so it is wise to check into such things when considering a school and your course of action.