We talk frequently – those of us who are paying attention – about the various policy proposals of the opposite sides in American politics. It goes back centuries; it predates our founding era, even. One side has one solution and the other side proposes an alternative; both sides debate, and eventually one option or the other is tried. Sometimes – and this is one of the goals of the idea of states’ rights – some states try one method and other states try the other. The “laboratories of democracy” concept is given its opportunity, and we can see which methods...