Eggzackly.
In the mid-term election that apparently plays a big role in the plot, the Democrats’ (Peace and War) primary strategy was to exacerbate racial antagonism. In the NYC draft riots of 1863, the rioters were largely, though not exclusively, focused on killing black men.
Haven’t seen the movie, and don’t know if I will, but I strongly suspect it portrays the Copperheads as 1970s Vietnam War resisters before their time.
Which is a shame. A much better movie could have been made by showing the complexity of the issue. That attitudes we applaud today (like pacifism) and those we despise (like virulent even for the time racism) were often inextricably linked.
Locating the movie in NY was also pretty odd, as the real Copperheads were concentrated in the midwest.
Afraid of deprogramming the reconstructed history that permeates your brain?