No. Any requests to change voter registration records must be received 3 weeks before the election.
Maryland's top two political parties, in their bylaws, declare who can vote in their primary election. A voter who insists on voting a different party ballot will be required to complete a provisional application and ballot. Then after the election, office staff will research to determine if a request was received before the deadline or if a clerical mistake was made. If neither situation applies, the ballot will be rejected. In any event, the voter will receive credit for voting.
Note: In a General Election, parties have no bearing and all voters may vote for any candidate, regardless of political affiliation.