ah, so the whistling really is too loud...
anyway, this is a state issue, not Fed. If the Fed wants to get involved and claim jurisdiction over a state's laws, that's really their issue, isn't it?
Anyway, explain how this will require a larger infrastructure than what is currently in place? It really becomes nothing more than alcohol and tobacco as part of the same branch of regulation. Sure, there will be a few increases in terms of putting things in place to keep home-growing in check and within legal limits, but that is also along the lines of home-brewing and distilling, for which every American already has annual legal limits (thank you, Jimmy Carter!

)
Granted, growing your own MJ will be much, much more popular than brewing.
Personally, I'd rather see larger government infrastructure set in place to regulate this if it shrinks the drug cartel and black market industry, which it invariably will. The potential revenue is insane. The crime reduction perhaps even more insane. You should love these things as a libertarian/conservative, rather than cry and scream and run in fear of this phantom big government boogey man that the Shepherds have drilled into your noggin.