It's predictable that it's coming from a conservative state. That they are broadly against using state power to ban things is part of their identity and marketing but not reality. Especially when it can be construed as a social-moral problem.
Like any political group, there's a wide variety of ideas. Religious right folks get lumped together with constitutional libertarians, but have very, very different ideas on the proper limits of legislation and government power.
And yes, there are both idiots and brilliant thinkers in the Republican party (which !== 'conservative'). There are very good ideas, and abominably stupid ones.
Much like any group of humans.
Next you'll tell me that there have been presidents that haven't lived up to their campaign promises...
States rights isn't just for social-moral topics such as marijuana and immigration. We should have expected it to be used for other things as has historically been the case.
California et al just had a slight lead.