The pro-Question 7 elements tout that bringing another casino to National Harbor and adding table games to all six would provide 12,000 jobs. Presumably some of these would be at the Baltimore site, not yet built, but what they are really talking about is National Harbor.
Look at a Prince George's County map. National Harbor is on the shore of the Potomac River, directly across the river from Virginia, and a short (but not necessary quick) drive across the Wilson Bridge. It's also about two miles from Washington, and a convenient drive out of the city down I-295.