INTRODUCTION

To give a sense of the politics of extreme parties, the Appendix lists all candidates in u.s. presidential elections who won at least half a percent of the popular vote. For each election year, the table lists candidates by my reading of their ideology, with the most conservative candidate listed at the top, and the most liberal candidate listed at the bottom. Candidates not belonging to one of the two major parties are shown with an asterisk after the party affiliation. Also shown is the percentage of the popular vote each won. The data begin with the election of 1832, the first election in which virtually all states chose presidential electors by popular vote.

Ordering parties by ideology entails some subjective judgment. A principal difficulty is that for much of the nineteenth century slavery and the consequences of the Civil War were the main issues, whereas in the twentieth century economic issues can distinguish parties. I classify Republicans as more liberal than Democrats through the election of 1872. From 1876 (when Reconstruction ended) and thereafter I classify Republicans as more conservative than Democrats.

Two features are of note:

1. • Third parties, even popular ones, rarely become major parties. Indeed, only one minor party, the Republican Party, ever became a major party.

2. • Most small parties have extreme ideologies, in the sense of not lying between the ideologies of the two major parties. Of the 41 elections, 28 had small parties which won at least 0.5 percent of the vote. Of these 28 elections, only four had a moderate party.[…]