TAILIANNA No it doesn't kill the discussion. the best example I can think of to try to explain this is, before same sex marriage was legalized across america, there were originally just a few states that allowed and recognized it, eventually more states started legalizing it until finally it was legalized across the US.
something similar is going on with Marijuana now. it's legal in a few states, other states it's legal with exceptions, even though the government hasn't legalized it across the country
The federal government is like a corporate headquarters. The HQ gives out policy(aka Federal Law) for the regional offices (aka the States) to follow. The states, aka regional offices, can take the HQs policy (aka Federal Law) and make more specific policies(aka State Law) that is most appropriate for them, for the local/ municipal offices(aka The cities and towns) to follow. the cities and towns, aka, the local/municipal offices, take the policies of their regional offices and create specific laws most appropriate for themselves. Does that make sense? Hope that helps.