Previous studies of the personal, political and attitudinal representativeness of primary electorates have produced mixed results. These analyses were based on single states or communities rather than a national sample, did not distinguish between general election voters who did not participate in the primary from those who did not vote in either election, and usually did not use verified voting participation measures. Using a national sample of verified voters, this study provides stronger support for the hypothesis that primary voters are unrepresentative of nonparticipants in important dimensions of political life.