There are some values more fundamental than others. One might be that inconsistency or hypocrisy is bad.
One might stipulate that whether marijuana should be illegal isn't an absolute that can never change.
But if it is in accordance with our values that it should be legal now, and this is our best attempt at instituting just laws, then leaving people in jail for reasons we don't currently think are valid is relatively worse than any arbitrary rule about drugs.
Just because you don't know for sure what is truly and absolutely right doesn't mean you can't stop doing things you know are truly and absolutely wrong.
Agreed, I think this is where I generally fall as well. Pragmatism as a philosophical discipline is often criticized as lacking a purity, but at some point we have to stop philosophizing and actually make policy.
One might stipulate that whether marijuana should be illegal isn't an absolute that can never change.
But if it is in accordance with our values that it should be legal now, and this is our best attempt at instituting just laws, then leaving people in jail for reasons we don't currently think are valid is relatively worse than any arbitrary rule about drugs.
Just because you don't know for sure what is truly and absolutely right doesn't mean you can't stop doing things you know are truly and absolutely wrong.