This thesis investigates core aspects of campaign strategy, through content analysis of campaign rhetoric, to assess whether there is evidence that campaign strategy changes, rather than remains fixed, during presidential general election campaigns. Campaign rhetoric is used as a proxy for campaign strategy as a whole. Established campaign strategy theory states that strategy should remain fixed, but the literature also suggests that changes may be made to campaign strategy. Through analysis of four core categories of campaign strategy: use of tone, character, issues and party, this paradox is investigated. Using content analysis, based on a number of codebooks, a comprehensive dataset of presidential campaign speeches are analysed. For the use of tone, issues and party, this is for all campaigns from 1960-2012. For the use of character this is for the 2004-2012 campaigns due to the more qualitative nature of this analysis. Each chapter presents findings relating to change in the use of each category. There are changes to the use of campaign strategy in all four categories, and in every campaign analysed. The final chapter proposes that rather than thinking of strategy as being fixed, campaign strategy should instead be understood in terms of periods of strategic stability, which are interjected with points of change. These may be minor or major strategic changes. The final chapter also tests potential explanations as to why change may occur, using regression analysis. Further research is necessary to determine specifically why changes occur in campaign strategy, as well as to determine if the findings also can be applied to other media of campaign strategy.