  We study the effects of campaigning, where the society is partitioned into
voter clusters and a diffusion process propagates opinions in a network
connecting the clusters. Our model is very powerful and can incorporate many
campaigning actions, various partitions of the society into clusters, and very
general diffusion processes. Perhaps surprisingly, we show that computing the
cheapest campaign for rigging a given election can usually be done efficiently,
even with arbitrarily-many voters. Moreover, we report on certain computational
simulations.
