This paper studies a simple dynamic model of pre-electoral opinion formation, where individuals repeatedly form their opinions as to which (out of two) candidate to support. The behavioral rules we analyze allow for various forms of discontinuities, that we characterize in terms of threshold, and are defined in a locally interactive setting. We focus on both the long-run and short-run behavior of the process. It is shown that the asymptotics of the process depend crucially on the particular form of discontinuity that we postulate. In particular the process may show a tendency towards consensus, in the sense that all individuals conform in their opinion, or the system may be absorbed in configurations in which different opinions co-exist. We finally analyze various forms of asymmetries in the threshold.