Assuming this analysis has no problems with method, it's likely that the separation of any two groups on a continuous spectrum cannot ever reach 100% accuracy.

Assuming this analysis has no problems with method, it's likely that the separation of any two groups on a continuous spectrum cannot ever reach 100% accuracy. In fact for such multivariate groupings as opposing political persuasion, 72% may in fact be as good a score as is possible. Representing the conservative and liberal groups as gaussian mixes of multiple atributes, I would expect those two peaks to overlap. Perhaps the real surprise is that they overlap no more than 28%.