All you have to do in DC is win, it's really immaterial how long you sucked before you started winning. Cultivating a fanbase is over rated, particularly in a town this transient. This isn't Milwaukee where people grow up, live and die in the same neighborhood. Win big in DC and the seats will be packed every night. That's just how we roll around here.
Conversely, lose and the seats will be empty. The only thing impervious to that are the Redskins, but after a decade of abuse at the hands of the Evil Snyder, even THAT passion is waning and I didn't think I'd ever see that in my lifetime. But like everything else, all the Skins need to do is win and everyone will be back again with a fury.