THE DECLINE OF THIRD PARTY VOTING IN THE UNITED STATES1

1We thank seminar participants at MIT and Columbia for helpful comments. This paper highlights a prominent but little discussed pattern in U.S. politics, which is the decline of third party electoral support during the second half of the twentieth century. Contrary to claims in the literature, we provide evidence that the introduction of the direct primaries and the Australian ballot are not correlated with an immediate decline of third party electoral support outside the South. Instead, we find evidence consistent with the claim that electoral support for third parties declined because the Democratic Party co-opted the left-wing policy position beginning with the passage of the New Deal agenda. After the New Deal the Democratic Party’s electoral support was higher in areas that had traditionally supported left-wing third parties. 1