








Policies are assumed to rarely change after enactment. Punctuated equilibrium theory argues this is because law makers shift attention away from policies after enactment, letting them run on autopilot. I argue that the periods between punctuations deserves study, and that what law makers do is design institutions to make policies path dependent so they can only change within limited parameters-if at all. It may also be that interest groups opposing new policies are still able to shape the way they evolve, pushing against intended paths. In this article I test the influence of path dependence versus group opposition in state charter school policies. I find some evidence of path dependence, but I also find that, to some extent, opposing interests can still change these laws after enactment. Furthermore, I find these policies became increasingly similar over time, partially because of path dependence, but also because of the influence of opposing interests.
