If states could oppose federal law slavery would still be part of southern culture. It is a well known fact, that slavery was considered a state, choice until the federal laws, deemed it illegal, after that the big war happened, and slavery was abolished, yay
but let's look at what would have happened if the states would have just said, no were not going to listen to you on this one, and the feds did nothing about it. This nation would still have slavery. Their is a reason that their is a federal law system, it's for when the state, is abusing it's power, and being unjust towards certain groups, of it's people.