Yeah, conservatives believe that in all cases state's rights trump all.

Conservatives fought that notion by opposing Dred Scot and Plessy v. Ferguson.
Can you muster a more compelling argument?
The first time a dope fiend slams into an SUV killing the mother driving and her children, and Colorado's laws prove insufficient to secure a conviction.... the drums will begin beating around the country for the feds to step in and correct the situation.
This experiment will prove to be short-lived. It's just a shame it blood will have to be shed to undo liberal madness. But that's what was needed to end slavery, wuzinit?