Gruesome spectacles of violence. Belief in ethno-religious supremacy. Fundamentalist notions of social order. Preoccupations with purity and vengeance. Recruitment tactics aimed at the disaffected and disenfranchised.

This describes ISIS's modus operandi as much as that of America's own homegrown brand of terrorism — a phenomenon at least as old as the Civil War and rooted in the nation's original sin.

Organized by embittered Confederate veterans, the Klu Klux Klan was established to advance the reinstatement of white supremacy in the newly reunited republic. Targeting all non-white, non-Protestant, and non-native-born residents of the United States, but above all African Americans, Klansmen waged a brutal campaign of terror — consisting of kidnappings, hangings, whippings, mutilation, and murder — prompting Congress under President Ulysses S. Grant to pass laws outlawing the KKK as a terrorist group.

But by then, the KKK had already begun to disband. With the advent of Jim Crow laws — which later earned Hitler's praise and admiration as a model of state-sanctioned racism — the Klan had largely achieved its goal. White supremacy had once again become the law of the land.

Fast-forward past two major revivals of the Klan to the post-9/11 era. Today, despite the mounting threat of racist violence to the very integrity of American democracy, far-right extremists are rarely prosecuted as terrorists. That fate is far more likely to fall on suspected "Islamists" with trumped-up affiliations to jihadist groups. Meanwhile, white supremacists organize, rally, and commit heinous crimes, often in the open. (And how many are held at Gitmo?)

Calls for domestic-terrorism laws may seem reasonable, but one should be wary. Current counterterrorism legislation is routinely and grossly abused. Black and Muslim Americans, as well as political dissidents of various stripes, are regularly and unjustly harassed by law enforcement. What's needed isn't a new suite of oppressive tools. Instead, what's needed is a reckoning with America's legacy of racially justified exploitation. Until such an unlikely moment of introspection, however, domestic terrorism will continue to flourish — as American an institution as baseball or apple pie.