Politics in Cornwall in the twentieth century was dominated by the rivalry of two major parties: the Conservatives and the Liberals. Unlike much of the rest of Britain Cornwall retained a different political paradigm in which Labour did not replace the old left, with socialism, and until the modern day this localised duopoly has persisted. This thesis looks at the potentially different reasons why this divergence persists and identifies three possible explanations for this phenomenon: culture, character and campaigns. In Part I of the thesis, there is a comparison of politicians from the past and the attributes that these politicians possessed which are compared with modern day politicians to evaluate their relative strengths. The thesis also assesses historic campaigning as a cause of Liberal success as well as the different nature of Cornwall, with its distance from Westminster and its Celtic and Methodist background, which set it apart from much of the rest of England. Then in Part II, using modern day voter surveys conducted by telephone, this thesis identifies particular peculiarities in Cornwall which would seem to suggest that although there have been traditional cultural ties to Liberalism, mainly through the pre-dominant faith, Methodism, this cleavage towards the modern day Liberal Democrats has changed in nature as cultural reasons have become less significant. It also identifies the importance of so-called personality politics, in the Cornish context, as a key aspect of maintaining and then augmenting support for the party. As such major personalities from historic Cornish politics, such as Isaac Foot and David Penhaligon, are compared to modern day politicians to assess their relative significance. However, the significant majority of the original research conducted across Cornwall, and other parts of the country, attempts to identify whether the resurgence of the Liberal Democrats in the 1997 election, and subsequently, is linked to the campaigning the party conducts rather than these traditional assumptions for their electoral success. Conducting telephone surveys across thirteen parliamentary constituencies, before and after the 2010 general election, from the Highlands of Scotland to West Cornwall, this research identifies that grassroots campaigning, commonly referred to as Rennardism in the most recent past, but more accurately described as Community Politics, is the primary reason for the success of the Liberal Democrats in Cornwall between 1997 and 2010. By assessing not just seats in which the Liberal Democrats have been successful in recent years in Cornwall but also in similar, and different, regions of Britain a better assessment of the value of the party’s successes and failures can be evaluated both in Cornwall and comparatively. The research compares different potential reasons for voters supporting the party but the evidence would seem to suggest that in the period under discussion the party had built substantial levels of campaigning capacity in the target areas for the party and this helped to win all the seats in Cornwall for the Liberal Democrats in 2005. Surveys were conducted before and after the 2010 election and there is also evidence that as the party became a less effective campaigning machine it began to lose support in Cornwall and this helps to explain why the party lost seats in Cornwall in 2010. This thesis adds to the increasing awareness, amongst political scientists, of the significance of local constituency campaigning, in British politics, which has been the subject of debate in this field in recent years. Historically scholars have debated the significance of national swing, with early political scientists, like David Butler and Robert Mackenzie, favouring this explanation to electoral success assessing the general election campaign as being essentially a national one. However, as three and now arguably four or even five party politics is the norm academics such as David Denver, Dennis Kavanagh and Philip Cowley have identified that constituency campaigning matters much more to those parties breaking into the post-war duopoly, than early political scientists have suggested. This thesis evaluates, not just whether there is a local campaign factor in the Liberal Democrats’ success, but whether the volume and penetration of this local campaign matters and, as such, this research is original and forms a unique contribution to academic debate in this field.