This article studies the persistent effects of past agrarian inequality on contemporary voting preferences. Although Western European countries became industrial (and later post-industrial) economies, the political effects of the agrarian cleavage are still visible in those countries in which the agrarian issue was dominant in the interwar period (the industrial laggards). Looking at the spatial variation in voting patterns in the fifteen elections held in Spain since 1977, we show through mediation analysis that areas with high historical agrarian inequality have higher levels of leftist vote. We examine two transmission channels: one economic (related to backwardness); the other political (related to family transmission of political allegiances). A survey analysis provides evidence in favour of family transmission. A brief exploration of other cases confirms the general argument: a similar effect is found in Italy (an industrial laggard), but not in England (an early industrializer).