This article seeks to introduce an alternative notion of time into the cross-sectional study of the causes and effects of interparty competition in the American states. Past studies which average interparty competition over long periods ignore important conceptual and methodological issues. As a result, some empirical findings which have acquired the status of conventional wisdom may be subject to question. It is suggested that many problems may be overcome by measuring interparty competition over very short periods of time. Sequential cross-sectional analysis identifies some relationships with interparty competition which are static over time and others which are dynamic over time.