“If it’s an al-Qaeda attack, you can bet it will affect the resources and how we respond to it,” [Daniel L.] Byman said. But “many of the objectives [of right-wing extremist groups] are close enough to legitimate political movements. It would be hard to take them on as a whole without causing a lot of discomfort” among people who don’t have violent aims.
This basically sums up why only Muslims, black separatists, defenders of the planet’s ecology and animal rights activists are treated as terrorists, with all the legal disabilities that entails, while white people who talk, meet, train and eventually kill people are never treated as terrorists. If the ideology which motivates you to violence meets the USA oligarchy’s approval, you can’t be a terrorist, no matter what you do.