In the hours after last summer’s white power rally in Charlottesville, Va., erupted into violence, the planners of the protest mounted a defense: While much of the country may have found their racist chants and Nazi iconography deplorable, they claimed that they had a First Amendment right to self-expression, and that none of the bloodshed was actually their fault.

Six months later, that narrative of blamelessness, which started on the airwaves and the internet, is now being tested in the courthouse. In a direct assault on the so-called alt-right movement, a sprawling lawsuit contends that the leaders of the Charlottesville gathering engaged in a conspiracy to foster racial hatred, and are legally responsible for the 30 injuries and the death of a woman, Heather Heyer, that occurred.

“There is one thing about this case that should be made crystal-clear at the outset,” the suit maintains. “The violence in Charlottesville was no accident.”

The case, known as Sines v. Kessler, was filed in October in Federal District Court in Charlottesville, and reached a crucial stage two weeks ago when the 15 individual defendants and the groups they represent finished filing motions to dismiss the case. In hundreds of pages of impassioned argument, the court submissions indicate that a bitter legal battle will soon be underway.