Honestly, the best thing they could probably do is figure out a way to build some triple-combination of racetrack/casino/fairgrounds out 95 in White Marsh or 795 in Owings Mills. Then you have a compromise of a Baltimore-area racetrack, in Maryland horse country, with highway (and possible Metro or MARC) access, two major events to structure the racetrack around (the Preakness weekend and State Fair), the other ancillary events that the current fairgrounds hosts, and, of course, a casino.
I'm confused. Build a new track out there north of the city, so it's not closer to DC. Have daily racing there, to build a culture that will support the Timonium and Pimlico facilities? Is that what you are implying?
If so, maybe just upgrade the Timonium facility which is closer to Hunt Valley where real horse racing culture is, and have more races there. Gotta be room to attach a casino there. You have the light rail right there.