From a reader:

I’m genuinely curious to know how Ramesh turned you against the plan given your federalist inclinations. I remember a very memorable
quote from your lecture here at Carleton about federalism being the
best system for “maximizing human happiness.” So what’s the problem
here? If the experiment fails, it’s Massachusetts’ problem; if it
succeeds, it might serve as a model for other states. Isn’t that
what federalism is all about? How can you say “Let the states
decide” and then say “But I don’t like this decision”?

Me: This is an easy one. I never questioned the right of Massachusetts to implement this law. Federalism doesn’t require me to withhold my opinion about state policy, does it? I don’t think anyone on the anti side thinks the federal government or courts should forbid a state from making mistakes along these lines.