There's a (one-sided) debate going on over at the Volokh Conspiracy about whether or not federalism is "tainted" in virtue of its history with Jim Crow, slavery, and racism generally. Much conservative hand-wringing ensues, and much cognitive dissonance is introduced. Ilya Somin, at one point, draws a tortured distinction between "federalism" and "states' rights" by claiming that the former "requires citizen mobility between states, so that people can 'vote with their feet' against jurisdictions that adopt harmful or oppressive policies toward them."
Uh, since when? I mean, I appreciate that it's more than a little bit awkward to be a decent proponent of federalism in a world in which defending the autonomy of individual states has been used as a pretext for implementing brutal, disgusting, racist policies. What aren't cool are the intellectual convolutions the rest of us have to listen to to hear why all federalists shouldn't be painted with the same brush. It's confusing and it's complicated, and it's all entirely unnecessary.
All you've really got to do to wash your hands of federalism's history, in my view, is to admit that federalism isn't a fundamental ethical principle. States aren't morally relevant entities, so we've got no basic ethical reason to start giving them rights. Federalism is ultimately just a useful rule of thumb for implementing policy effectively and justly arranging institutions. The difference isn't hard to see, but a lot of conservatives are emotionally wedded to their federalism, so there's a lot of reluctance to recognize it. Among other things, acknowledging that distinction would mean that modern-day federalists would have to start defending their stances in terms of actual costs and benefits rather than lazy appeals to abstract principle, but that's just so much the worse for modern-day federalists.
Certainly, that would take some of the wind out of federalism's sails, but that's the price you pay for having elevated the whole philosophy so high in the first place.