Federalism
Again, the idea of "Federalism" seems to change markedly depending on who's looking at it and what is involved. Both Left and Right have done their share of cherry-picking on what should be local issues and what shouldn't, and "interpreting" the Constitution accordingly.
Tell ya what. Next time, let's change abortion laws on a community-by-community bases. I seem to have missed the Amendment in the Bill of Rights dealing with that issue.