Assuming my translation is accurate, Cinco de Mayo is tomorrow in Columbia Heights, and some local spots are having events. Social at 14th and Meridian NW has $5 margaritas or $25 pitchers, plus $1.50 fish tacos and $3 guacamole and blood orange pico de gallo. Plus they now have sidewalk seating.
I would assume newly opened Alero has deals as well, and Taqueria Distrito Federal might be a good spot to get some traditional grub, deals or not.
Know of any other deals in the neighborhood? Interestingly, apparently Cinco de Mayo is not such a big deal in Mexico -- 16 de septiembre is the big one.