They'll dwarf all but the very largest existing lobbying powerhouses and the same people who now control the worst democrat lobby groups will control the new ones.
Conservatives can easily get into the mold of telling everyone else what to do just as the left does.
The drug lobby wants to keep pot illegal so they can continue foist deadly, addictive meds on the populous for the reason that only they can produce, sell and profit from highly controlled substances. (Legal sales of pot are only the beginning to growing your own.) Pot would wipe out the antidepressant business as well as much of the pain killers.