Oh! I was using "center-X" vs "far-X" as a distinction. The same distinction could be expressed maybe as "X" vs "radical-X" — the Democrats are "rightist" and the Republicans are "radical rightist" — much in the same way that we might say that social-democrats are "leftist" and revolutionary communists are "radical leftist".

A good non-radical leader can be one who is a good manager of the current system, who gently reforms it toward social goals. However, radicals would never accept such a milquetoast weakling; they want someone who will come in, smash everything, "drain the swamp", and implement the dictatorship of ... um ... someone.