To "champion states' rights" is to take the wrong perspective. You spoke of the small "L" style libertarian, your complaint seems more fitting of the the party (large "L"), which formally supports the Constitution as fundamental law, & opposes government's taking more authority than is granted them therein. Decentralization of authority is inherent in this law, ie, the fed has some powers, & others are reserved for the states. Consider how the fed ban on gay marriage has been successfully challenged by states which legalized it. What we champion is liberty, but the political system to achieve it is merely a tool to that end.