An issue in the making since 1978
In the dark of night, Annapolis legislators eliminated the right of Maryland grocery stores to sell alcohol. Friends of the liquor lobby removed chains' ability to obtain one store per county and outright banned chain store sales. The chains through the Maryland Food Dealers Council (now Maryland Retailers Association) spent three years fighting to get it back ... but failed.
As a result, there are now 20 legacy stores grandfathered into Maryland law. You may have shopped at these stores and wondered how they can sell alcohol but not the others in the chain. This is why.
There have been a number of efforts over the years to bring back competition, all without success.