We study an organized market for votes, in which trade is directed by
a market ''specialist''. This market mechanism always produces an equi
librium outcome, and whenever vote buying occurs the alternative chose
n is Pareto superior to the alternative that would be chosen without t
rade. We then characterize the equilibrium outcomes in a one-dimension
al policy space, and show that if the distribution of ideal points is
skewed enough, then the equilibrium with vote buying differs from the
equilibrium without vote buying (the median ideal point). This differe
nce reflects the ability of an intense minority to obtain a policy it
prefers in exchange for side-payments.