You could definitely draw 4 GOP districts in MD, and in 2000 you could have drawn 4 GOP districts and a liberal MD-08 that would have been held by RINO Connie Morella. The easiest way would be to draw a white ultraliberal CD in Montco, a black-majority CD taking in all of Baltimore City (including the white parts currently in MD-03) and a few suburbs, a black-majority CD taking in the western Baltco suburbs, most of Howard County and black areas in PG County, and a third black-majority district takin in most of PG County, less heavily white parts of Montco and most of Charles County. The four GOP CDs would be (i) the Eastern Shore plus most of Southern Maryland (which, DJ correct me if I’m wrong, were together prior to 1992), (ii) all of Ann Arundel County, parts of Baltco and most if not all of Harford County, (iii) most of Baltco (excluding Dem areas) and Carrol County and (iv) the Western Panhandle plus less heavily Democrat parts of Montco and Howard Counties.
But, of course, the Democrats control redistricting. I wonder if they’ll try to draw 7 comfortably Democrat districts, which could be done, especially if they draw two Montco-based white CDs (one taking in Frederick and Hagerstown, the other taking in parts of Ann Arundel and white parts of PG) and draw two black-majority CDs based in PG County that also take in parts of Southern MD and the Eastern Shore (which votes GOP but has quite a few blacks and would be swamped by the 90%+ margins in black PG precincts), one of which could continue up until eastern Baltimore City.
The 1st district (when the apostate Gilchrest first won it in '90) consisted of the entire Eastern Shore, half of the eastern half of Harford County, and even Charles, St. Mary's and Calvert County on the western side. For '92, Harford was put wholly into the 2nd (then Helen Bentley's district, later Ehrlich's), and the three western shore counties were put into the newly-configured 5th district (of which that gave Hoyer some trouble with nailing down after he first ran in it).
I still wonder if even with the most optimistic lines if we could squeeze 4 seats now given the drop-off in GOP support. Even Bartlett gave his 3rd worst performance (excluding his '82 run), although his advancing age probably played a part, too. Wasn't Alexander X. Mooney, a Hispanic State Senator from Frederick, supposed to be the odds-on candidate to succeed him ?