Tomorrow's Unite the Right 2: Ethnocentric Boogalo in DC promises to be a real shitshow. My suggestion for a counter to the rally is echoed in this plan to block attendees from parking at the Vienna, VA metro station. A similar denial of parking tactic used in Vancouver, WA, stymied transportation to the recent Portland 'Patriot Prayer' shitshow. The best tactic to use against these assholes is one of 'jamming'- force them to expend more effort to get to and from the destination- fill up the trains, cluster in the streets going toward Lafayette Park. Most of the attendees will be outsiders... force them to find alternative transportation, make them walk blocks out of their way to get to where they want to be. There's no need to engage with them, simply amble along the streets like clueless tourists, making frequent stops in order to obstruct the sidewalks. Make the out-of-towners feel 'all at sea', many of them aren't city folk, and are unused to the congestion of an inner city- frustrate them simply by living as an urbanite. Deny them a foothold, and do it in a manner that they can't even counter. Mess with their logistics.
Also, deny them any comfort, figure out where the public bathrooms are and occupy them, restrict them from your places of business, make them use up resources like gasoline and bottled water. It's supposed to be a stormy day in DC, deny them a place to get out of the rain. These people want their little war, give them confusion. I'm a judo player, and our sport is about controlling, rather than injuring them (though we are capable of messing someone up, it's not our purpose)... control the movements of these assholes, control the unfamiliar (to them) urban environment. There's no need to be confrontational, simply show them how insignificant they are in a large, diverse metropolitan environment