The closed primaries versus the top-two primary

The top-two primary recently approved in states like Washington, California, and Alaska eliminates the closed party primaries and creates instead a single ballot in which the first and second place winners pass to the general election. We compare the electoral consequences of the top-two primary with those of the closed primaries. We present a model where each primary procedure induce a sequential game with three stages: candidate-entry stage, primary election, and general election. We analyze the equilibria of these games and show that the top-two primary contributes to political moderation and may increase the number of swing states.