The paper inquires to the structural and geographic peculiarities of electoral behaviour. The link with territorial dimension of structural components and electoral dynamics becomes the focus of the analysis. In this essay the employ of Sistema Locale del Lavoro (SLL) - local labour district - is proposed as unit for the analysis of electoral behaviour in order to investigate the relationship with socio-economic dimensions. To study clustered territorial units, several measures have been formalised for economic and demographic analysis but, and this is our hypothesis, they are valid also for the study of electoral behaviour: localisation measures. The application tries to define the units according their different electoral behaviour. The interest of the study, namely, is focalised upon the political parties much more linked to the territorial dimension: Lega Nord and Movimento per l’Autonomia.