Well, now we know that at least one of the four candidates at the top of the tickets believes in federalism:
As the Republican vice-presidential nominee Rep. Paul Ryan gets ready to begin debate preparation on Sunday in Oregon, the Wisconsin lawmaker raised a few eyebrows when he told KRDO-TV in Colorado Springs that states should have the right to choose whether to legalize the drug for medical purposes. Ryan emphasized that while he doesn’t personally approve of laws that make medicinal marijuana legal, “it’s up to Coloradans to decide.” Colorado is one of 17 states, plus Washington, D.C., that allow medicinal marijuana, notes the Associated Press.
Dangerous stuff, this. It's easy to be for federalism when you disagree with what's happening at the national level. "The Supreme Court should have left abortion to the states" is code for "Abortion is evil." Or did you suppose that pro-life advocates would have been pleased if a majority of states went pro-choice?
It's much harder to maintain your belief in federalism when faced with the possibility states may not choose to your liking, or to the liking of your followers, which seems to be the case here with Ryan. That's the thing about freedom -- people may not use it the way you wish they would. This is like, oh, requiring doctors to just treat the patient and not make judgments on whether the patient is worthy of saving, or insisting that attorneys give their clients the best defense possible whatever they think of their guilt or innocence. We have to take the long-term view that the principle exists for a reason and remains necessary for a reason. Asking for exceptions when you don't like the way the vote is going will do far more harm than leaving the "wrong" vote alone.