This is unpacked a bit further on in Thoburn's introduction:
In Deleuze and Guattari's monist thought, then, 'life' has no primary forms or identities but is a perpetual process of configuration and variation, where politics is an art of composition, an art that affirms the variation and creation of life: "'molecular' or 'minor' processes, against striation and identity", 'major' or 'molar' processes... The ramifications of this generalization of politics across the plane of life are great, and this maneuver plays a not insignificant part in the positive reception and use of Deleuze and Guattari's works in recent years, where a frequent theme is an explication of this politicized life in a 'politics of becoming'.
In A Thousand Plateaus, Deleuze and Guattari explain:
The race-tribe exists only at the level of an oppressed race, and in the name of the oppression it suffers: there is no race but inferior, minoritarian; there is no dominant race; a race is defined not by its purity, but rather by the impurity conferred upon it by a system of domination. Bastard and mixed-blood are the true names of race. (379)
Immediately following this, they invoke the Rimbaud we discussed above about self-identification with racial aleatoriness and inferiority:
It’s obvious to me I’ve always belonged to an inferior race. I don’t understand rebellion. My race never rose up except to pillage: like wolves round a beast they haven’t killed. (Rimbaud, A Season in Hell)
Just a page later, they explain a bit further about the nomad:
The nomad has a territory; he follows customary paths; he goes from one point to another; he is not ignorant of points (water points, dwelling points, assembly points, etc.). But the question is what in nomad life is a principle and what is only a consequence. To begin with, although the points determine paths, they are strictly subordinated to the paths they determine, the reverse happens with the sedentary. The water point is reached only in order to be left behind; every point is a relay and exists only as a relay. A path is always between two points, but the in-between has taken on all the consistency and enjoys both an autonomy and a direction of its own. The life of the nomad is the intermezzo. (380)
Deleuze and Race looks like it explores some of the anti-racist elements of D+G's philosophy pretty thoroughly -- might be worth a look.