I'm not entirely sure. Typically, a DUI conviction in Maryland is classified as a misdemeanor not a felony. Since DHS typically acts on non-citizen with felony convictions, a DUI alone might not trigger action. However, the policy in this case seems to originate from the Admissibility Review Office, which operates under CBP. If your DMV records show a license revocation or any similar trigger related to your license, they may want to escalate the matter to a federal level. They seem to aim for standardizing the punishment and aligning the crime definitions with their CBP policy.

In other words, it's a Trump way, or take a highway to your country.