The lack of overwhelming police presence is exactly what I think the White Supremacist instigators of this rally wanted: violent confrontation, blood, headlines.
Both citizens and protestors complained that the Charlottesville police couldn't or wouldn't protect them. Crowd control, to say nothing of riot control, requires that every officer stick to the plan, to hold his designated position. Whenever a fight breaks out and officers abandoned their posts guarding entry and exit points, the entire crowd control plan breaks down and the potential for chaos grows even further.
Nor, when the crowds begin to disperse and then re-condense on streets deep into the city grid, did the police have any chance of both completing their main objective, moving people out of the park, and being present to douse every flaring of tempers and flaling of fists.
Sure, the City of Charlottesville could have recruited officers from nearby cities to augment their ranks, but who is going to pay those officers for their time? Their travel? Their meals? Their motel rooms?
And don't forget a riot cops do not spring full form from the badge. Instead, troops have to train, train together, draw equipment, and walk through many scenarios. Properly policing the White Power riots would have been an prohibitively expensive proposition.
Surely the city of Charlottesville is not expected to make an extra tax levy against it's own citizens for a million or so dollars to pay to protect a demonstration they never invited, went to court to try to stop, and, in the end, did the best they could with what they had.
And Richard Spencer and his contingent of merry troublemakers played on the weaknesses of the Charlottesville PD by insisting no other place would do.
The Neo-Nazis got exactly what they wanted: dramatic footage and pictures, lots of confrontations, and mayhem that the neo-Nazis could not have accomplished in a major metropolitan area.
Charlottesville was victimized twice. Once by the White Supremacist and again by the Federal Courts.