The most sweeping lawsuit against the promoters of the Charlottesville white power rally has been churning toward trial for two years, ever since hundreds of white supremacists and Nazis staged a torch-lit march that set off a weekend of violence.

In that time, lawyers have been methodically pursuing a case that could demonstrate how to use the courts to combat extremism in an age when the internet has provided a global megaphone for ideas once limited to an isolated fringe.

The outcome is not a foregone conclusion. A closer look at the legal strategy in the lawsuit, known as Sines v. Kessler, illustrates the hurdles involved in putting hate and intolerance in the dock, with members of the far right habitually citing the First Amendment as their shield.

To pursue participants in the Charlottesville rally, lawyers are relying on 21st century technology as well as a seldom-invoked law from the Civil War era.