Nagel and Wlezien (2010) found that the Liberal Democrats in Britain tended to gain votes when the Conservatives moved to the right on the left-right spectrum, and the Labour Party moved to the left. They also found that, as the Liberal Democrats gained votes, they pushed the Conservatives to the right, but not Labour. Nagel and Wlezien took their left-right measurements from the Comparative Manifesto Project (CMP) This thesis studies whether these phenomena occur cross-nationally across other advanced democracies. Using a dataset of 26 established wealthy democracies, mainly long-term members of the Organisation for Economic Cooperation and Development, this work measures whether increased distance between conservative and social democratic parties benefits parties in the liberal party family. The thesis finds that the dynamics that Nagel and Wlezien observed in Great Britain appear in other democracies more generally. It also finds that liberal party strength pushes conservatives farther to the right (which Nagel and Wlezien found in Britain) and social democrats farther to the left (which was not the case in Britain). The work also tests how more general measures of polarization impact liberal parties, finding either no impact or an unexpected negative association. Finally, the work concluded with an examination of the role of some liberal parties as players in the postmaterialist arena, and provides a qualitative study of some new parties which are being or which may be classified as liberal.