You are in fact, correct. MD DOES require that one register their automobile and get a MD driver's license if an individual is residing (owns, leases or rents residential property) in MD for more than 6 months. If you haven't changed everything over after 6 months, you can be charged with driving an unregistered vehicle and driving on an improper license.
COMAR 11.11.06.02
For income tax reasons, MD considers a person a "resident of MD" if they have lived in MD for more than 12 months, REGARDLESS of the fact that they may own property in another state, or have not established residency in MD by properly and lawfully changing their DL and vehicle registration over to MD. (
Tax General Article of the MD Code 10-101)
Rahm was, if he in fact DIDN'T register his vehicle, change his DL to MD, and failed to pay MD income tax, breaking the law.
But in MD, the law is different for people like Rahm. There are, apparently, a set of super-secret laws and statutes in MD for powerful, wealthy, and well-connected individuals that are not on the books, or available in any library or website. These laws are apparently written in invisible ink, and can only be made visible by the application of copious amounts of campaign contributions to the Governor, though they sometimes become visible in the presence of tremendous political power, and sometimes they also are visible magically to people who have over-inflated senses of aristocratic entitlement...
The "color of law" in Maryland is Green and Gold...